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drh75897232000-05-29 14:26:00 +00001/*
drhb19a2bc2001-09-16 00:13:26 +00002** 2001 September 15
drh75897232000-05-29 14:26:00 +00003**
drhb19a2bc2001-09-16 00:13:26 +00004** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
drh75897232000-05-29 14:26:00 +00006**
drhb19a2bc2001-09-16 00:13:26 +00007** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
drh75897232000-05-29 14:26:00 +000010**
11*************************************************************************
drhb19a2bc2001-09-16 00:13:26 +000012** This header file defines the interface that the SQLite library
drh6ed48bf2007-06-14 20:57:18 +000013** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
drh75897232000-05-29 14:26:00 +000017**
drh6ed48bf2007-06-14 20:57:18 +000018** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
mihailima3f64902008-06-21 13:35:56 +000020** features recently added to SQLite. We do not anticipate changes
shane7c7c3112009-08-17 15:31:23 +000021** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
drh6ed48bf2007-06-14 20:57:18 +000023**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are suppose to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
drh75897232000-05-29 14:26:00 +000032*/
drh12057d52004-09-06 17:34:12 +000033#ifndef _SQLITE3_H_
34#define _SQLITE3_H_
drha18c5682000-10-08 22:20:57 +000035#include <stdarg.h> /* Needed for the definition of va_list */
drh75897232000-05-29 14:26:00 +000036
37/*
drh382c0242001-10-06 16:33:02 +000038** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
drh6d2069d2007-08-14 01:58:53 +000044
drh382c0242001-10-06 16:33:02 +000045/*
drh73be5012007-08-08 12:11:21 +000046** Add the ability to override 'extern'
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51
52/*
drh4d6618f2008-09-22 17:54:46 +000053** These no-op macros are used in front of interfaces to mark those
54** interfaces as either deprecated or experimental. New applications
shane7c7c3112009-08-17 15:31:23 +000055** should not use deprecated interfaces - they are support for backwards
drh4d6618f2008-09-22 17:54:46 +000056** compatibility only. Application writers should be aware that
57** experimental interfaces are subject to change in point releases.
58**
59** These macros used to resolve to various kinds of compiler magic that
60** would generate warning messages when they were used. But that
61** compiler magic ended up generating such a flurry of bug reports
62** that we have taken it all out and gone back to using simple
63** noop macros.
shanea79c3cc2008-08-11 17:27:01 +000064*/
drh4d6618f2008-09-22 17:54:46 +000065#define SQLITE_DEPRECATED
66#define SQLITE_EXPERIMENTAL
shanea79c3cc2008-08-11 17:27:01 +000067
68/*
mihailim362cc832008-06-21 06:16:42 +000069** Ensure these symbols were not defined by some previous header file.
drhb86ccfb2003-01-28 23:13:10 +000070*/
drh1e284f42004-10-06 15:52:01 +000071#ifdef SQLITE_VERSION
72# undef SQLITE_VERSION
drh1e284f42004-10-06 15:52:01 +000073#endif
drh6ed48bf2007-06-14 20:57:18 +000074#ifdef SQLITE_VERSION_NUMBER
75# undef SQLITE_VERSION_NUMBER
76#endif
danielk197799ba19e2005-02-05 07:33:34 +000077
78/*
drh1e15c032009-12-08 15:16:54 +000079** CAPI3REF: Compile-Time Library Version Numbers
drh6ed48bf2007-06-14 20:57:18 +000080**
drh1e15c032009-12-08 15:16:54 +000081** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
82** evaluates to a string literal that is the SQLite version in the
83** format "X.Y.Z" where X is the major version number (always 3 for
84** SQLite3) and Y is the minor version number and Z is the release number.)^
85** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
86** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
87** numbers used in [SQLITE_VERSION].)^
88** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
89** be larger than the release from which it is derived. Either Y will
90** be held constant and Z will be incremented or else Y will be incremented
91** and Z will be reset to zero.
drh6aa5f152009-08-19 15:57:07 +000092**
drh47baebc2009-08-14 16:01:24 +000093** Since version 3.6.18, SQLite source code has been stored in the
drh1e15c032009-12-08 15:16:54 +000094** <a href="http://www.fossil-scm.org/">Fossil configuration management
95** system</a>. ^The SQLITE_SOURCE_ID macro evalutes to
96** a string which identifies a particular check-in of SQLite
97** within its configuration management system. ^The SQLITE_SOURCE_ID
98** string contains the date and time of the check-in (UTC) and an SHA1
99** hash of the entire source tree.
drh47baebc2009-08-14 16:01:24 +0000100**
drh6aa5f152009-08-19 15:57:07 +0000101** See also: [sqlite3_libversion()],
drh4e0b31c2009-09-02 19:04:24 +0000102** [sqlite3_libversion_number()], [sqlite3_sourceid()],
103** [sqlite_version()] and [sqlite_source_id()].
danielk197799ba19e2005-02-05 07:33:34 +0000104*/
drh47baebc2009-08-14 16:01:24 +0000105#define SQLITE_VERSION "--VERS--"
106#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--
107#define SQLITE_SOURCE_ID "--SOURCE-ID--"
drhb86ccfb2003-01-28 23:13:10 +0000108
109/*
drh1e15c032009-12-08 15:16:54 +0000110** CAPI3REF: Run-Time Library Version Numbers
drh33c1be32008-01-30 16:16:14 +0000111** KEYWORDS: sqlite3_version
drh6ed48bf2007-06-14 20:57:18 +0000112**
drh47baebc2009-08-14 16:01:24 +0000113** These interfaces provide the same information as the [SQLITE_VERSION],
drh1e15c032009-12-08 15:16:54 +0000114** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
drhd68eee02009-12-11 03:44:18 +0000115** but are associated with the library instead of the header file. ^(Cautious
drh4e0b31c2009-09-02 19:04:24 +0000116** programmers might include assert() statements in their application to
117** verify that values returned by these interfaces match the macros in
118** the header, and thus insure that the application is
drh6aa5f152009-08-19 15:57:07 +0000119** compiled with matching library and header files.
120**
121** <blockquote><pre>
122** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
drh4e0b31c2009-09-02 19:04:24 +0000123** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
drh1e15c032009-12-08 15:16:54 +0000124** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
drhd68eee02009-12-11 03:44:18 +0000125** </pre></blockquote>)^
drh6ed48bf2007-06-14 20:57:18 +0000126**
drh1e15c032009-12-08 15:16:54 +0000127** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
128** macro. ^The sqlite3_libversion() function returns a pointer to the
129** to the sqlite3_version[] string constant. The sqlite3_libversion()
130** function is provided for use in DLLs since DLL users usually do not have
131** direct access to string constants within the DLL. ^The
132** sqlite3_libversion_number() function returns an integer equal to
133** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function a pointer
134** to a string constant whose value is the same as the [SQLITE_SOURCE_ID]
135** C preprocessor macro.
drh33c1be32008-01-30 16:16:14 +0000136**
drh4e0b31c2009-09-02 19:04:24 +0000137** See also: [sqlite_version()] and [sqlite_source_id()].
drhb217a572000-08-22 13:40:18 +0000138*/
drh73be5012007-08-08 12:11:21 +0000139SQLITE_EXTERN const char sqlite3_version[];
drha3f70cb2004-09-30 14:24:50 +0000140const char *sqlite3_libversion(void);
drh47baebc2009-08-14 16:01:24 +0000141const char *sqlite3_sourceid(void);
danielk197799ba19e2005-02-05 07:33:34 +0000142int sqlite3_libversion_number(void);
143
144/*
drhd68eee02009-12-11 03:44:18 +0000145** CAPI3REF: Test To See If The Library Is Threadsafe
146**
147** ^The sqlite3_threadsafe() function returns zero if and only if
148** SQLite was compiled mutexing code omitted due to the
149** [SQLITE_THREADSAFE] compile-time option being set to 0.
drhb67e8bf2007-08-30 20:09:48 +0000150**
drh33c1be32008-01-30 16:16:14 +0000151** SQLite can be compiled with or without mutexes. When
drh6aa5f152009-08-19 15:57:07 +0000152** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
drhafacce02008-09-02 21:35:03 +0000153** are enabled and SQLite is threadsafe. When the
154** [SQLITE_THREADSAFE] macro is 0,
drh33c1be32008-01-30 16:16:14 +0000155** the mutexes are omitted. Without the mutexes, it is not safe
mihailim362cc832008-06-21 06:16:42 +0000156** to use SQLite concurrently from more than one thread.
drhb67e8bf2007-08-30 20:09:48 +0000157**
mihailim362cc832008-06-21 06:16:42 +0000158** Enabling mutexes incurs a measurable performance penalty.
drh33c1be32008-01-30 16:16:14 +0000159** So if speed is of utmost importance, it makes sense to disable
160** the mutexes. But for maximum safety, mutexes should be enabled.
drhd68eee02009-12-11 03:44:18 +0000161** ^The default behavior is for mutexes to be enabled.
drh33c1be32008-01-30 16:16:14 +0000162**
drh6aa5f152009-08-19 15:57:07 +0000163** This interface can be used by an application to make sure that the
drh33c1be32008-01-30 16:16:14 +0000164** version of SQLite that it is linking against was compiled with
drh4766b292008-06-26 02:53:02 +0000165** the desired setting of the [SQLITE_THREADSAFE] macro.
166**
167** This interface only reports on the compile-time mutex setting
168** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
drhd68eee02009-12-11 03:44:18 +0000169** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
drh4766b292008-06-26 02:53:02 +0000170** can be fully or partially disabled using a call to [sqlite3_config()]
171** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
drhd68eee02009-12-11 03:44:18 +0000172** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
173** sqlite3_threadsafe() function shows only the compile-time setting of
174** thread safety, not any run-time changes to that setting made by
175** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
176** is unchanged by calls to sqlite3_config().)^
drh33c1be32008-01-30 16:16:14 +0000177**
drhafacce02008-09-02 21:35:03 +0000178** See the [threading mode] documentation for additional information.
drhb67e8bf2007-08-30 20:09:48 +0000179*/
180int sqlite3_threadsafe(void);
181
182/*
drhd68eee02009-12-11 03:44:18 +0000183** CAPI3REF: Database Connection Handle
drha06f17f2008-05-11 11:07:06 +0000184** KEYWORDS: {database connection} {database connections}
drh6ed48bf2007-06-14 20:57:18 +0000185**
mihailim362cc832008-06-21 06:16:42 +0000186** Each open SQLite database is represented by a pointer to an instance of
187** the opaque structure named "sqlite3". It is useful to think of an sqlite3
drh8bacf972007-08-25 16:21:29 +0000188** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
mihailim362cc832008-06-21 06:16:42 +0000189** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
190** is its destructor. There are many other interfaces (such as
191** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
192** [sqlite3_busy_timeout()] to name but three) that are methods on an
193** sqlite3 object.
drh75897232000-05-29 14:26:00 +0000194*/
drh9bb575f2004-09-06 17:24:11 +0000195typedef struct sqlite3 sqlite3;
danielk197765904932004-05-26 06:18:37 +0000196
drh75897232000-05-29 14:26:00 +0000197/*
drhd68eee02009-12-11 03:44:18 +0000198** CAPI3REF: 64-Bit Integer Types
drh33c1be32008-01-30 16:16:14 +0000199** KEYWORDS: sqlite_int64 sqlite_uint64
drh6ed48bf2007-06-14 20:57:18 +0000200**
drh33c1be32008-01-30 16:16:14 +0000201** Because there is no cross-platform way to specify 64-bit integer types
drhfddfa2d2007-12-05 18:05:16 +0000202** SQLite includes typedefs for 64-bit signed and unsigned integers.
drh6ed48bf2007-06-14 20:57:18 +0000203**
mihailim362cc832008-06-21 06:16:42 +0000204** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
205** The sqlite_int64 and sqlite_uint64 types are supported for backwards
206** compatibility only.
drh33c1be32008-01-30 16:16:14 +0000207**
drhd68eee02009-12-11 03:44:18 +0000208** ^The sqlite3_int64 and sqlite_int64 types can store integer values
209** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
210** sqlite3_uint64 and sqlite_uint64 types can store integer values
211** between 0 and +18446744073709551615 inclusive.
drhefad9992004-06-22 12:13:55 +0000212*/
drh27436af2006-03-28 23:57:17 +0000213#ifdef SQLITE_INT64_TYPE
drh9b8f4472006-04-04 01:54:55 +0000214 typedef SQLITE_INT64_TYPE sqlite_int64;
drh27436af2006-03-28 23:57:17 +0000215 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
216#elif defined(_MSC_VER) || defined(__BORLANDC__)
drhefad9992004-06-22 12:13:55 +0000217 typedef __int64 sqlite_int64;
drh1211de32004-07-26 12:24:22 +0000218 typedef unsigned __int64 sqlite_uint64;
drhefad9992004-06-22 12:13:55 +0000219#else
220 typedef long long int sqlite_int64;
drh1211de32004-07-26 12:24:22 +0000221 typedef unsigned long long int sqlite_uint64;
drhefad9992004-06-22 12:13:55 +0000222#endif
drh6d2069d2007-08-14 01:58:53 +0000223typedef sqlite_int64 sqlite3_int64;
224typedef sqlite_uint64 sqlite3_uint64;
drhefad9992004-06-22 12:13:55 +0000225
drhb37df7b2005-10-13 02:09:49 +0000226/*
227** If compiling for a processor that lacks floating point support,
mihailim362cc832008-06-21 06:16:42 +0000228** substitute integer for floating-point.
drhb37df7b2005-10-13 02:09:49 +0000229*/
230#ifdef SQLITE_OMIT_FLOATING_POINT
drh6d2069d2007-08-14 01:58:53 +0000231# define double sqlite3_int64
drhb37df7b2005-10-13 02:09:49 +0000232#endif
drhefad9992004-06-22 12:13:55 +0000233
234/*
drhd68eee02009-12-11 03:44:18 +0000235** CAPI3REF: Closing A Database Connection
drh75897232000-05-29 14:26:00 +0000236**
drhd68eee02009-12-11 03:44:18 +0000237** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
238** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
239** successfullly destroyed and all associated resources are deallocated.
drh33c1be32008-01-30 16:16:14 +0000240**
drh7db29fb2009-10-20 14:23:09 +0000241** Applications must [sqlite3_finalize | finalize] all [prepared statements]
mihailim15194222008-06-22 09:55:14 +0000242** and [sqlite3_blob_close | close] all [BLOB handles] associated with
drhd68eee02009-12-11 03:44:18 +0000243** the [sqlite3] object prior to attempting to close the object. ^If
244** sqlite3_close() is called on a [database connection] that still has
245** outstanding [prepared statements] or [BLOB handles], then it returns
246** SQLITE_BUSY.
drh55b0cf02008-06-19 17:54:33 +0000247**
drhd68eee02009-12-11 03:44:18 +0000248** ^If [sqlite3_close()] is invoked while a transaction is open,
drh55b0cf02008-06-19 17:54:33 +0000249** the transaction is automatically rolled back.
drh33c1be32008-01-30 16:16:14 +0000250**
drh8b39db12009-02-18 18:37:58 +0000251** The C parameter to [sqlite3_close(C)] must be either a NULL
252** pointer or an [sqlite3] object pointer obtained
253** from [sqlite3_open()], [sqlite3_open16()], or
254** [sqlite3_open_v2()], and not previously closed.
drhd68eee02009-12-11 03:44:18 +0000255** ^Calling sqlite3_close() with a NULL pointer argument is a
256** harmless no-op.
drh75897232000-05-29 14:26:00 +0000257*/
danielk1977f9d64d22004-06-19 08:18:07 +0000258int sqlite3_close(sqlite3 *);
drh75897232000-05-29 14:26:00 +0000259
260/*
261** The type for a callback function.
drh6ed48bf2007-06-14 20:57:18 +0000262** This is legacy and deprecated. It is included for historical
263** compatibility and is not documented.
drh75897232000-05-29 14:26:00 +0000264*/
drh12057d52004-09-06 17:34:12 +0000265typedef int (*sqlite3_callback)(void*,int,char**, char**);
drh75897232000-05-29 14:26:00 +0000266
267/*
drhd68eee02009-12-11 03:44:18 +0000268** CAPI3REF: One-Step Query Execution Interface
drh6ed48bf2007-06-14 20:57:18 +0000269**
drhd68eee02009-12-11 03:44:18 +0000270** The sqlite3_exec() interface is a convenience wrapper around
271** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
272** that allows an application to run multiple statements of SQL
273** without having to use a lot of C code.
drh75897232000-05-29 14:26:00 +0000274**
drhd68eee02009-12-11 03:44:18 +0000275** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
276** semicolon-separate SQL statements passed into its 2nd argument,
277** in the context of the [database connection] passed in as its 1st
278** argument. ^If the callback function of the 3rd argument to
279** sqlite3_exec() is not NULL, then it is invoked for each result row
280** coming out of the evaluated SQL statements. ^The 4th argument to
281** to sqlite3_exec() is relayed through to the 1st argument of each
282** callback invocation. ^If the callback pointer to sqlite3_exec()
283** is NULL, then no callback is ever invoked and result rows are
284** ignored.
drh35c61902008-05-20 15:44:30 +0000285**
drhd68eee02009-12-11 03:44:18 +0000286** ^If an error occurs while evaluating the SQL statements passed into
287** sqlite3_exec(), then execution of the current statement stops and
288** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
289** is not NULL then any error message is written into memory obtained
290** from [sqlite3_malloc()] and passed back through the 5th parameter.
291** To avoid memory leaks, the application should invoke [sqlite3_free()]
292** on error message strings returned through the 5th parameter of
293** of sqlite3_exec() after the error message string is no longer needed.
294** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
295** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
296** NULL before returning.
drh35c61902008-05-20 15:44:30 +0000297**
drhd68eee02009-12-11 03:44:18 +0000298** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
299** routine returns SQLITE_ABORT without invoking the callback again and
300** without running any subsequent SQL statements.
drh75897232000-05-29 14:26:00 +0000301**
drhd68eee02009-12-11 03:44:18 +0000302** ^The 2nd argument to the sqlite3_exec() callback function is the
303** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
304** callback is an array of pointers to strings obtained as if from
305** [sqlite3_column_text()], one for each column. ^If an element of a
306** result row is NULL then the corresponding string pointer for the
307** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
308** sqlite3_exec() callback is an array of pointers to strings where each
309** entry represents the name of corresponding result column as obtained
310** from [sqlite3_column_name()].
mihailima3f64902008-06-21 13:35:56 +0000311**
drhd68eee02009-12-11 03:44:18 +0000312** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
313** to an empty string, or a pointer that contains only whitespace and/or
314** SQL comments, then no SQL statements are evaluated and the database
315** is not changed.
drh75897232000-05-29 14:26:00 +0000316**
drhd68eee02009-12-11 03:44:18 +0000317** Restrictions:
drh75897232000-05-29 14:26:00 +0000318**
drhd68eee02009-12-11 03:44:18 +0000319** <ul>
320** <li> The application must insure that the 1st parameter to sqlite3_exec()
321** is a valid and open [database connection].
322** <li> The application must not close [database connection] specified by
323** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
324** <li> The application must not modify the SQL statement text passed into
325** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
326** </ul>
drh75897232000-05-29 14:26:00 +0000327*/
danielk19776f8a5032004-05-10 10:34:51 +0000328int sqlite3_exec(
drh6ed48bf2007-06-14 20:57:18 +0000329 sqlite3*, /* An open database */
shane236ce972008-05-30 15:35:30 +0000330 const char *sql, /* SQL to be evaluated */
drh6ed48bf2007-06-14 20:57:18 +0000331 int (*callback)(void*,int,char**,char**), /* Callback function */
332 void *, /* 1st argument to callback */
333 char **errmsg /* Error msg written here */
drh75897232000-05-29 14:26:00 +0000334);
335
drh58b95762000-06-02 01:17:37 +0000336/*
drhd68eee02009-12-11 03:44:18 +0000337** CAPI3REF: Result Codes
drh33c1be32008-01-30 16:16:14 +0000338** KEYWORDS: SQLITE_OK {error code} {error codes}
mihailimefc8e8a2008-06-21 16:47:09 +0000339** KEYWORDS: {result code} {result codes}
drh6ed48bf2007-06-14 20:57:18 +0000340**
341** Many SQLite functions return an integer result code from the set shown
drh33c1be32008-01-30 16:16:14 +0000342** here in order to indicates success or failure.
drh6ed48bf2007-06-14 20:57:18 +0000343**
drh4766b292008-06-26 02:53:02 +0000344** New error codes may be added in future versions of SQLite.
345**
drh6ed48bf2007-06-14 20:57:18 +0000346** See also: [SQLITE_IOERR_READ | extended result codes]
drh58b95762000-06-02 01:17:37 +0000347*/
drh717e6402001-09-27 03:22:32 +0000348#define SQLITE_OK 0 /* Successful result */
drh15b9a152006-01-31 20:49:13 +0000349/* beginning-of-error-codes */
drh717e6402001-09-27 03:22:32 +0000350#define SQLITE_ERROR 1 /* SQL error or missing database */
drh89e0dde2007-12-12 12:25:21 +0000351#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
drh717e6402001-09-27 03:22:32 +0000352#define SQLITE_PERM 3 /* Access permission denied */
353#define SQLITE_ABORT 4 /* Callback routine requested an abort */
354#define SQLITE_BUSY 5 /* The database file is locked */
355#define SQLITE_LOCKED 6 /* A table in the database is locked */
356#define SQLITE_NOMEM 7 /* A malloc() failed */
357#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
drh24cd67e2004-05-10 16:18:47 +0000358#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
drh717e6402001-09-27 03:22:32 +0000359#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
360#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
drh2db0bbc2005-08-11 02:10:18 +0000361#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */
drh717e6402001-09-27 03:22:32 +0000362#define SQLITE_FULL 13 /* Insertion failed because database is full */
363#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
drh4f0ee682007-03-30 20:43:40 +0000364#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */
drh24cd67e2004-05-10 16:18:47 +0000365#define SQLITE_EMPTY 16 /* Database is empty */
drh717e6402001-09-27 03:22:32 +0000366#define SQLITE_SCHEMA 17 /* The database schema changed */
drhc797d4d2007-05-08 01:08:49 +0000367#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
danielk19776eb91d22007-09-21 04:27:02 +0000368#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
drh8aff1012001-12-22 14:49:24 +0000369#define SQLITE_MISMATCH 20 /* Data type mismatch */
drh247be432002-05-10 05:44:55 +0000370#define SQLITE_MISUSE 21 /* Library used incorrectly */
drh8766c342002-11-09 00:33:15 +0000371#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
drhed6c8672003-01-12 18:02:16 +0000372#define SQLITE_AUTH 23 /* Authorization denied */
drh1c2d8412003-03-31 00:30:47 +0000373#define SQLITE_FORMAT 24 /* Auxiliary database format error */
danielk19776f8a5032004-05-10 10:34:51 +0000374#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
drhc602f9a2004-02-12 19:01:04 +0000375#define SQLITE_NOTADB 26 /* File opened that is not a database file */
danielk19776f8a5032004-05-10 10:34:51 +0000376#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
377#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
drh15b9a152006-01-31 20:49:13 +0000378/* end-of-error-codes */
drh717e6402001-09-27 03:22:32 +0000379
drhaf9ff332002-01-16 21:00:27 +0000380/*
drhd68eee02009-12-11 03:44:18 +0000381** CAPI3REF: Extended Result Codes
drh33c1be32008-01-30 16:16:14 +0000382** KEYWORDS: {extended error code} {extended error codes}
mihailimefc8e8a2008-06-21 16:47:09 +0000383** KEYWORDS: {extended result code} {extended result codes}
drh4ac285a2006-09-15 07:28:50 +0000384**
drh6ed48bf2007-06-14 20:57:18 +0000385** In its default configuration, SQLite API routines return one of 26 integer
mihailim362cc832008-06-21 06:16:42 +0000386** [SQLITE_OK | result codes]. However, experience has shown that many of
387** these result codes are too coarse-grained. They do not provide as
drhf5befa02007-12-06 02:42:07 +0000388** much information about problems as programmers might like. In an effort to
drh6ed48bf2007-06-14 20:57:18 +0000389** address this, newer versions of SQLite (version 3.3.8 and later) include
390** support for additional result codes that provide more detailed information
drh33c1be32008-01-30 16:16:14 +0000391** about errors. The extended result codes are enabled or disabled
mihailim362cc832008-06-21 06:16:42 +0000392** on a per database connection basis using the
393** [sqlite3_extended_result_codes()] API.
mihailima3f64902008-06-21 13:35:56 +0000394**
drh33c1be32008-01-30 16:16:14 +0000395** Some of the available extended result codes are listed here.
396** One may expect the number of extended result codes will be expand
397** over time. Software that uses extended result codes should expect
398** to see new result codes in future releases of SQLite.
drh4ac285a2006-09-15 07:28:50 +0000399**
400** The SQLITE_OK result code will never be extended. It will always
401** be exactly zero.
drh4ac285a2006-09-15 07:28:50 +0000402*/
danielk1977861f7452008-06-05 11:39:11 +0000403#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
404#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
405#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
406#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
407#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
408#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
409#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
410#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
411#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
412#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
413#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
414#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
415#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
416#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
aswift5b1a2562008-08-22 00:22:35 +0000417#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
aswiftaebf4132008-11-21 00:10:35 +0000418#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
419#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
danielk1977404ca072009-03-16 13:19:36 +0000420#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) )
421
drh4ac285a2006-09-15 07:28:50 +0000422/*
drhd68eee02009-12-11 03:44:18 +0000423** CAPI3REF: Flags For File Open Operations
drh6d2069d2007-08-14 01:58:53 +0000424**
mlcreechb2799412008-03-07 03:20:31 +0000425** These bit values are intended for use in the
drh33c1be32008-01-30 16:16:14 +0000426** 3rd parameter to the [sqlite3_open_v2()] interface and
427** in the 4th parameter to the xOpen method of the
drhd84f9462007-08-15 11:28:56 +0000428** [sqlite3_vfs] object.
drh6d2069d2007-08-14 01:58:53 +0000429*/
shane089b0a42009-05-14 03:21:28 +0000430#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
431#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
432#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
433#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
434#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
435#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
436#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
437#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
438#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
439#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
440#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
441#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
442#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
443#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
drhf1f12682009-09-09 14:17:52 +0000444#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
445#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
drh6d2069d2007-08-14 01:58:53 +0000446
447/*
drhd68eee02009-12-11 03:44:18 +0000448** CAPI3REF: Device Characteristics
drh6d2069d2007-08-14 01:58:53 +0000449**
drh33c1be32008-01-30 16:16:14 +0000450** The xDeviceCapabilities method of the [sqlite3_io_methods]
drhfddfa2d2007-12-05 18:05:16 +0000451** object returns an integer which is a vector of the these
drh6d2069d2007-08-14 01:58:53 +0000452** bit values expressing I/O characteristics of the mass storage
453** device that holds the file that the [sqlite3_io_methods]
drh33c1be32008-01-30 16:16:14 +0000454** refers to.
drh6d2069d2007-08-14 01:58:53 +0000455**
drh33c1be32008-01-30 16:16:14 +0000456** The SQLITE_IOCAP_ATOMIC property means that all writes of
457** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
drh6d2069d2007-08-14 01:58:53 +0000458** mean that writes of blocks that are nnn bytes in size and
459** are aligned to an address which is an integer multiple of
drh33c1be32008-01-30 16:16:14 +0000460** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
drh6d2069d2007-08-14 01:58:53 +0000461** that when data is appended to a file, the data is appended
462** first then the size of the file is extended, never the other
drh33c1be32008-01-30 16:16:14 +0000463** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
drh6d2069d2007-08-14 01:58:53 +0000464** information is written to disk in the same order as calls
465** to xWrite().
466*/
467#define SQLITE_IOCAP_ATOMIC 0x00000001
468#define SQLITE_IOCAP_ATOMIC512 0x00000002
469#define SQLITE_IOCAP_ATOMIC1K 0x00000004
470#define SQLITE_IOCAP_ATOMIC2K 0x00000008
471#define SQLITE_IOCAP_ATOMIC4K 0x00000010
472#define SQLITE_IOCAP_ATOMIC8K 0x00000020
473#define SQLITE_IOCAP_ATOMIC16K 0x00000040
474#define SQLITE_IOCAP_ATOMIC32K 0x00000080
475#define SQLITE_IOCAP_ATOMIC64K 0x00000100
476#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
477#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
478
479/*
drhd68eee02009-12-11 03:44:18 +0000480** CAPI3REF: File Locking Levels
drh6d2069d2007-08-14 01:58:53 +0000481**
drh33c1be32008-01-30 16:16:14 +0000482** SQLite uses one of these integer values as the second
drh6d2069d2007-08-14 01:58:53 +0000483** argument to calls it makes to the xLock() and xUnlock() methods
drh33c1be32008-01-30 16:16:14 +0000484** of an [sqlite3_io_methods] object.
drh6d2069d2007-08-14 01:58:53 +0000485*/
486#define SQLITE_LOCK_NONE 0
487#define SQLITE_LOCK_SHARED 1
488#define SQLITE_LOCK_RESERVED 2
489#define SQLITE_LOCK_PENDING 3
490#define SQLITE_LOCK_EXCLUSIVE 4
491
492/*
drhd68eee02009-12-11 03:44:18 +0000493** CAPI3REF: Synchronization Type Flags
drh6d2069d2007-08-14 01:58:53 +0000494**
drh33c1be32008-01-30 16:16:14 +0000495** When SQLite invokes the xSync() method of an
mlcreechb2799412008-03-07 03:20:31 +0000496** [sqlite3_io_methods] object it uses a combination of
drhfddfa2d2007-12-05 18:05:16 +0000497** these integer values as the second argument.
drh6d2069d2007-08-14 01:58:53 +0000498**
drh33c1be32008-01-30 16:16:14 +0000499** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
drh6d2069d2007-08-14 01:58:53 +0000500** sync operation only needs to flush data to mass storage. Inode
drheb0d6292009-04-04 14:04:58 +0000501** information need not be flushed. If the lower four bits of the flag
502** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
503** If the lower four bits equal SQLITE_SYNC_FULL, that means
shane7ba429a2008-11-10 17:08:49 +0000504** to use Mac OS X style fullsync instead of fsync().
drh6d2069d2007-08-14 01:58:53 +0000505*/
drh6d2069d2007-08-14 01:58:53 +0000506#define SQLITE_SYNC_NORMAL 0x00002
507#define SQLITE_SYNC_FULL 0x00003
508#define SQLITE_SYNC_DATAONLY 0x00010
509
drh6d2069d2007-08-14 01:58:53 +0000510/*
drhd68eee02009-12-11 03:44:18 +0000511** CAPI3REF: OS Interface Open File Handle
drh6d2069d2007-08-14 01:58:53 +0000512**
drh6aa5f152009-08-19 15:57:07 +0000513** An [sqlite3_file] object represents an open file in the
514** [sqlite3_vfs | OS interface layer]. Individual OS interface
515** implementations will
drh6d2069d2007-08-14 01:58:53 +0000516** want to subclass this object by appending additional fields
drh4ff7fa02007-09-01 18:17:21 +0000517** for their own use. The pMethods entry is a pointer to an
drhd84f9462007-08-15 11:28:56 +0000518** [sqlite3_io_methods] object that defines methods for performing
519** I/O operations on the open file.
drh6d2069d2007-08-14 01:58:53 +0000520*/
521typedef struct sqlite3_file sqlite3_file;
522struct sqlite3_file {
drh153c62c2007-08-24 03:51:33 +0000523 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
drh6d2069d2007-08-14 01:58:53 +0000524};
525
526/*
drhd68eee02009-12-11 03:44:18 +0000527** CAPI3REF: OS Interface File Virtual Methods Object
drh6d2069d2007-08-14 01:58:53 +0000528**
drh4766b292008-06-26 02:53:02 +0000529** Every file opened by the [sqlite3_vfs] xOpen method populates an
530** [sqlite3_file] object (or, more commonly, a subclass of the
531** [sqlite3_file] object) with a pointer to an instance of this object.
532** This object defines the methods used to perform various operations
533** against the open file represented by the [sqlite3_file] object.
drhd84f9462007-08-15 11:28:56 +0000534**
drh9afedcc2009-06-19 22:50:31 +0000535** If the xOpen method sets the sqlite3_file.pMethods element
536** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
537** may be invoked even if the xOpen reported that it failed. The
538** only way to prevent a call to xClose following a failed xOpen
539** is for the xOpen to set the sqlite3_file.pMethods element to NULL.
540**
drhfddfa2d2007-12-05 18:05:16 +0000541** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
542** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
shane7ba429a2008-11-10 17:08:49 +0000543** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
mihailim362cc832008-06-21 06:16:42 +0000544** flag may be ORed in to indicate that only the data of the file
545** and not its inode needs to be synced.
mihailima3f64902008-06-21 13:35:56 +0000546**
drhd84f9462007-08-15 11:28:56 +0000547** The integer values to xLock() and xUnlock() are one of
drh4ff7fa02007-09-01 18:17:21 +0000548** <ul>
549** <li> [SQLITE_LOCK_NONE],
drh79491ab2007-09-04 12:00:00 +0000550** <li> [SQLITE_LOCK_SHARED],
drh4ff7fa02007-09-01 18:17:21 +0000551** <li> [SQLITE_LOCK_RESERVED],
552** <li> [SQLITE_LOCK_PENDING], or
553** <li> [SQLITE_LOCK_EXCLUSIVE].
554** </ul>
mihailima3f64902008-06-21 13:35:56 +0000555** xLock() increases the lock. xUnlock() decreases the lock.
mihailim362cc832008-06-21 06:16:42 +0000556** The xCheckReservedLock() method checks whether any database connection,
557** either in this process or in some other process, is holding a RESERVED,
drhd84f9462007-08-15 11:28:56 +0000558** PENDING, or EXCLUSIVE lock on the file. It returns true
mihailim362cc832008-06-21 06:16:42 +0000559** if such a lock exists and false otherwise.
mihailima3f64902008-06-21 13:35:56 +0000560**
drhcc6bb3e2007-08-31 16:11:35 +0000561** The xFileControl() method is a generic interface that allows custom
562** VFS implementations to directly control an open file using the
mihailim362cc832008-06-21 06:16:42 +0000563** [sqlite3_file_control()] interface. The second "op" argument is an
mihailima3f64902008-06-21 13:35:56 +0000564** integer opcode. The third argument is a generic pointer intended to
mihailim362cc832008-06-21 06:16:42 +0000565** point to a structure that may contain arguments or space in which to
drhcc6bb3e2007-08-31 16:11:35 +0000566** write return values. Potential uses for xFileControl() might be
567** functions to enable blocking locks with timeouts, to change the
568** locking strategy (for example to use dot-file locks), to inquire
drh9e33c2c2007-08-31 18:34:59 +0000569** about the status of a lock, or to break stale locks. The SQLite
mihailima3f64902008-06-21 13:35:56 +0000570** core reserves all opcodes less than 100 for its own use.
drh4ff7fa02007-09-01 18:17:21 +0000571** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
mihailim362cc832008-06-21 06:16:42 +0000572** Applications that define a custom xFileControl method should use opcodes
drh9e33c2c2007-08-31 18:34:59 +0000573** greater than 100 to avoid conflicts.
drhd84f9462007-08-15 11:28:56 +0000574**
575** The xSectorSize() method returns the sector size of the
576** device that underlies the file. The sector size is the
577** minimum write that can be performed without disturbing
578** other bytes in the file. The xDeviceCharacteristics()
579** method returns a bit vector describing behaviors of the
580** underlying device:
581**
582** <ul>
drh4ff7fa02007-09-01 18:17:21 +0000583** <li> [SQLITE_IOCAP_ATOMIC]
584** <li> [SQLITE_IOCAP_ATOMIC512]
585** <li> [SQLITE_IOCAP_ATOMIC1K]
586** <li> [SQLITE_IOCAP_ATOMIC2K]
587** <li> [SQLITE_IOCAP_ATOMIC4K]
588** <li> [SQLITE_IOCAP_ATOMIC8K]
589** <li> [SQLITE_IOCAP_ATOMIC16K]
590** <li> [SQLITE_IOCAP_ATOMIC32K]
591** <li> [SQLITE_IOCAP_ATOMIC64K]
592** <li> [SQLITE_IOCAP_SAFE_APPEND]
593** <li> [SQLITE_IOCAP_SEQUENTIAL]
drhd84f9462007-08-15 11:28:56 +0000594** </ul>
595**
596** The SQLITE_IOCAP_ATOMIC property means that all writes of
597** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
598** mean that writes of blocks that are nnn bytes in size and
599** are aligned to an address which is an integer multiple of
600** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
601** that when data is appended to a file, the data is appended
602** first then the size of the file is extended, never the other
603** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
604** information is written to disk in the same order as calls
605** to xWrite().
drh4c17c3f2008-11-07 00:06:18 +0000606**
607** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
608** in the unread portions of the buffer with zeros. A VFS that
609** fails to zero-fill short reads might seem to work. However,
610** failure to zero-fill short reads will eventually lead to
611** database corruption.
drh6d2069d2007-08-14 01:58:53 +0000612*/
613typedef struct sqlite3_io_methods sqlite3_io_methods;
614struct sqlite3_io_methods {
615 int iVersion;
616 int (*xClose)(sqlite3_file*);
drh79491ab2007-09-04 12:00:00 +0000617 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
618 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
619 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
drh6d2069d2007-08-14 01:58:53 +0000620 int (*xSync)(sqlite3_file*, int flags);
drh79491ab2007-09-04 12:00:00 +0000621 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
drh6d2069d2007-08-14 01:58:53 +0000622 int (*xLock)(sqlite3_file*, int);
623 int (*xUnlock)(sqlite3_file*, int);
danielk1977861f7452008-06-05 11:39:11 +0000624 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
drhcc6bb3e2007-08-31 16:11:35 +0000625 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
drh6d2069d2007-08-14 01:58:53 +0000626 int (*xSectorSize)(sqlite3_file*);
627 int (*xDeviceCharacteristics)(sqlite3_file*);
628 /* Additional methods may be added in future releases */
629};
630
631/*
drhd68eee02009-12-11 03:44:18 +0000632** CAPI3REF: Standard File Control Opcodes
drh9e33c2c2007-08-31 18:34:59 +0000633**
634** These integer constants are opcodes for the xFileControl method
mihailim362cc832008-06-21 06:16:42 +0000635** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
drh9e33c2c2007-08-31 18:34:59 +0000636** interface.
637**
drh33c1be32008-01-30 16:16:14 +0000638** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
mlcreechb2799412008-03-07 03:20:31 +0000639** opcode causes the xFileControl method to write the current state of
drh9e33c2c2007-08-31 18:34:59 +0000640** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
641** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
drh33c1be32008-01-30 16:16:14 +0000642** into an integer that the pArg argument points to. This capability
drh9e33c2c2007-08-31 18:34:59 +0000643** is used during testing and only needs to be supported when SQLITE_TEST
644** is defined.
645*/
646#define SQLITE_FCNTL_LOCKSTATE 1
aswiftaebf4132008-11-21 00:10:35 +0000647#define SQLITE_GET_LOCKPROXYFILE 2
648#define SQLITE_SET_LOCKPROXYFILE 3
649#define SQLITE_LAST_ERRNO 4
drh9e33c2c2007-08-31 18:34:59 +0000650
651/*
drhd68eee02009-12-11 03:44:18 +0000652** CAPI3REF: Mutex Handle
drh6d2069d2007-08-14 01:58:53 +0000653**
drhd84f9462007-08-15 11:28:56 +0000654** The mutex module within SQLite defines [sqlite3_mutex] to be an
drh33c1be32008-01-30 16:16:14 +0000655** abstract type for a mutex object. The SQLite core never looks
656** at the internal representation of an [sqlite3_mutex]. It only
drhd84f9462007-08-15 11:28:56 +0000657** deals with pointers to the [sqlite3_mutex] object.
drh6bdec4a2007-08-16 19:40:16 +0000658**
659** Mutexes are created using [sqlite3_mutex_alloc()].
drh6d2069d2007-08-14 01:58:53 +0000660*/
661typedef struct sqlite3_mutex sqlite3_mutex;
662
663/*
drhd68eee02009-12-11 03:44:18 +0000664** CAPI3REF: OS Interface Object
drh6d2069d2007-08-14 01:58:53 +0000665**
mihailim362cc832008-06-21 06:16:42 +0000666** An instance of the sqlite3_vfs object defines the interface between
667** the SQLite core and the underlying operating system. The "vfs"
drhd84f9462007-08-15 11:28:56 +0000668** in the name of the object stands for "virtual file system".
drh6d2069d2007-08-14 01:58:53 +0000669**
mihailim362cc832008-06-21 06:16:42 +0000670** The value of the iVersion field is initially 1 but may be larger in
671** future versions of SQLite. Additional fields may be appended to this
drh4766b292008-06-26 02:53:02 +0000672** object when the iVersion value is increased. Note that the structure
673** of the sqlite3_vfs object changes in the transaction between
674** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
675** modified.
drh6bdec4a2007-08-16 19:40:16 +0000676**
drh4ff7fa02007-09-01 18:17:21 +0000677** The szOsFile field is the size of the subclassed [sqlite3_file]
drhd84f9462007-08-15 11:28:56 +0000678** structure used by this VFS. mxPathname is the maximum length of
679** a pathname in this VFS.
680**
drhb4d58ae2008-02-21 20:17:06 +0000681** Registered sqlite3_vfs objects are kept on a linked list formed by
drh79491ab2007-09-04 12:00:00 +0000682** the pNext pointer. The [sqlite3_vfs_register()]
683** and [sqlite3_vfs_unregister()] interfaces manage this list
684** in a thread-safe way. The [sqlite3_vfs_find()] interface
drh4766b292008-06-26 02:53:02 +0000685** searches the list. Neither the application code nor the VFS
686** implementation should use the pNext pointer.
drhd84f9462007-08-15 11:28:56 +0000687**
mihailima3f64902008-06-21 13:35:56 +0000688** The pNext field is the only field in the sqlite3_vfs
drh1cc8c442007-08-24 16:08:29 +0000689** structure that SQLite will ever modify. SQLite will only access
690** or modify this field while holding a particular static mutex.
691** The application should never modify anything within the sqlite3_vfs
692** object once the object has been registered.
693**
drhd84f9462007-08-15 11:28:56 +0000694** The zName field holds the name of the VFS module. The name must
695** be unique across all VFS modules.
696**
drh032ca702008-12-10 11:44:30 +0000697** SQLite will guarantee that the zFilename parameter to xOpen
drh4766b292008-06-26 02:53:02 +0000698** is either a NULL pointer or string obtained
699** from xFullPathname(). SQLite further guarantees that
700** the string will be valid and unchanged until xClose() is
drh9afedcc2009-06-19 22:50:31 +0000701** called. Because of the previous sentence,
drh4766b292008-06-26 02:53:02 +0000702** the [sqlite3_file] can safely store a pointer to the
drh6d2069d2007-08-14 01:58:53 +0000703** filename if it needs to remember the filename for some reason.
drh4766b292008-06-26 02:53:02 +0000704** If the zFilename parameter is xOpen is a NULL pointer then xOpen
drh9afedcc2009-06-19 22:50:31 +0000705** must invent its own temporary name for the file. Whenever the
drh4766b292008-06-26 02:53:02 +0000706** xFilename parameter is NULL it will also be the case that the
707** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
drhd84f9462007-08-15 11:28:56 +0000708**
drh032ca702008-12-10 11:44:30 +0000709** The flags argument to xOpen() includes all bits set in
drhf5befa02007-12-06 02:42:07 +0000710** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
711** or [sqlite3_open16()] is used, then flags includes at least
drh032ca702008-12-10 11:44:30 +0000712** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
drh6d2069d2007-08-14 01:58:53 +0000713** If xOpen() opens a file read-only then it sets *pOutFlags to
mihailim362cc832008-06-21 06:16:42 +0000714** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
715**
drh032ca702008-12-10 11:44:30 +0000716** SQLite will also add one of the following flags to the xOpen()
drh6d2069d2007-08-14 01:58:53 +0000717** call, depending on the object being opened:
mihailim362cc832008-06-21 06:16:42 +0000718**
drh6d2069d2007-08-14 01:58:53 +0000719** <ul>
720** <li> [SQLITE_OPEN_MAIN_DB]
721** <li> [SQLITE_OPEN_MAIN_JOURNAL]
722** <li> [SQLITE_OPEN_TEMP_DB]
723** <li> [SQLITE_OPEN_TEMP_JOURNAL]
drh33f4e022007-09-03 15:19:34 +0000724** <li> [SQLITE_OPEN_TRANSIENT_DB]
drh6d2069d2007-08-14 01:58:53 +0000725** <li> [SQLITE_OPEN_SUBJOURNAL]
726** <li> [SQLITE_OPEN_MASTER_JOURNAL]
drh032ca702008-12-10 11:44:30 +0000727** </ul>
drhd84f9462007-08-15 11:28:56 +0000728**
drh6d2069d2007-08-14 01:58:53 +0000729** The file I/O implementation can use the object type flags to
mihailim362cc832008-06-21 06:16:42 +0000730** change the way it deals with files. For example, an application
mlcreechb2799412008-03-07 03:20:31 +0000731** that does not care about crash recovery or rollback might make
732** the open of a journal file a no-op. Writes to this journal would
mihailim362cc832008-06-21 06:16:42 +0000733** also be no-ops, and any attempt to read the journal would return
734** SQLITE_IOERR. Or the implementation might recognize that a database
735** file will be doing page-aligned sector reads and writes in a random
mlcreechb2799412008-03-07 03:20:31 +0000736** order and set up its I/O subsystem accordingly.
mihailim362cc832008-06-21 06:16:42 +0000737**
738** SQLite might also add one of the following flags to the xOpen method:
739**
drh6d2069d2007-08-14 01:58:53 +0000740** <ul>
741** <li> [SQLITE_OPEN_DELETEONCLOSE]
742** <li> [SQLITE_OPEN_EXCLUSIVE]
743** </ul>
mihailim362cc832008-06-21 06:16:42 +0000744**
drh032ca702008-12-10 11:44:30 +0000745** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
746** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE]
mihailim362cc832008-06-21 06:16:42 +0000747** will be set for TEMP databases, journals and for subjournals.
mihailim04bcc002008-06-22 10:21:27 +0000748**
shane089b0a42009-05-14 03:21:28 +0000749** The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
750** with the [SQLITE_OPEN_CREATE] flag, which are both directly
751** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
752** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
753** SQLITE_OPEN_CREATE, is used to indicate that file should always
754** be created, and that it is an error if it already exists.
755** It is <i>not</i> used to indicate the file should be opened
756** for exclusive access.
mihailim362cc832008-06-21 06:16:42 +0000757**
drh032ca702008-12-10 11:44:30 +0000758** At least szOsFile bytes of memory are allocated by SQLite
mihailim362cc832008-06-21 06:16:42 +0000759** to hold the [sqlite3_file] structure passed as the third
drh032ca702008-12-10 11:44:30 +0000760** argument to xOpen. The xOpen method does not have to
drh9afedcc2009-06-19 22:50:31 +0000761** allocate the structure; it should just fill it in. Note that
762** the xOpen method must set the sqlite3_file.pMethods to either
763** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
764** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
765** element will be valid after xOpen returns regardless of the success
766** or failure of the xOpen call.
mihailim362cc832008-06-21 06:16:42 +0000767**
drh032ca702008-12-10 11:44:30 +0000768** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
mihailim362cc832008-06-21 06:16:42 +0000769** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
770** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
drh032ca702008-12-10 11:44:30 +0000771** to test whether a file is at least readable. The file can be a
drh6d2069d2007-08-14 01:58:53 +0000772** directory.
mihailim362cc832008-06-21 06:16:42 +0000773**
drh032ca702008-12-10 11:44:30 +0000774** SQLite will always allocate at least mxPathname+1 bytes for the
775** output buffer xFullPathname. The exact size of the output buffer
776** is also passed as a parameter to both methods. If the output buffer
mihailim362cc832008-06-21 06:16:42 +0000777** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
778** handled as a fatal error by SQLite, vfs implementations should endeavor
779** to prevent this by setting mxPathname to a sufficiently large value.
780**
drhd84f9462007-08-15 11:28:56 +0000781** The xRandomness(), xSleep(), and xCurrentTime() interfaces
782** are not strictly a part of the filesystem, but they are
783** included in the VFS structure for completeness.
drh6d2069d2007-08-14 01:58:53 +0000784** The xRandomness() function attempts to return nBytes bytes
785** of good-quality randomness into zOut. The return value is
mihailim362cc832008-06-21 06:16:42 +0000786** the actual number of bytes of randomness obtained.
787** The xSleep() method causes the calling thread to sleep for at
drhd84f9462007-08-15 11:28:56 +0000788** least the number of microseconds given. The xCurrentTime()
mihailim362cc832008-06-21 06:16:42 +0000789** method returns a Julian Day Number for the current date and time.
drh032ca702008-12-10 11:44:30 +0000790**
drh6d2069d2007-08-14 01:58:53 +0000791*/
drhd84f9462007-08-15 11:28:56 +0000792typedef struct sqlite3_vfs sqlite3_vfs;
793struct sqlite3_vfs {
drh6d2069d2007-08-14 01:58:53 +0000794 int iVersion; /* Structure version number */
795 int szOsFile; /* Size of subclassed sqlite3_file */
drh6d2069d2007-08-14 01:58:53 +0000796 int mxPathname; /* Maximum file pathname length */
drhd84f9462007-08-15 11:28:56 +0000797 sqlite3_vfs *pNext; /* Next registered VFS */
drhd84f9462007-08-15 11:28:56 +0000798 const char *zName; /* Name of this virtual file system */
drh1cc8c442007-08-24 16:08:29 +0000799 void *pAppData; /* Pointer to application-specific data */
drh153c62c2007-08-24 03:51:33 +0000800 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
drh6d2069d2007-08-14 01:58:53 +0000801 int flags, int *pOutFlags);
drh153c62c2007-08-24 03:51:33 +0000802 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
danielk1977861f7452008-06-05 11:39:11 +0000803 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
danielk1977adfb9b02007-09-17 07:02:56 +0000804 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
drh153c62c2007-08-24 03:51:33 +0000805 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
806 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
drh1875f7a2008-12-08 18:19:17 +0000807 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
drh153c62c2007-08-24 03:51:33 +0000808 void (*xDlClose)(sqlite3_vfs*, void*);
809 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
810 int (*xSleep)(sqlite3_vfs*, int microseconds);
811 int (*xCurrentTime)(sqlite3_vfs*, double*);
danielk1977bcb97fe2008-06-06 15:49:29 +0000812 int (*xGetLastError)(sqlite3_vfs*, int, char *);
drhd84f9462007-08-15 11:28:56 +0000813 /* New fields may be appended in figure versions. The iVersion
drh6d2069d2007-08-14 01:58:53 +0000814 ** value will increment whenever this happens. */
815};
816
drh50d3f902007-08-27 21:10:36 +0000817/*
drhd68eee02009-12-11 03:44:18 +0000818** CAPI3REF: Flags for the xAccess VFS method
drh50d3f902007-08-27 21:10:36 +0000819**
drh032ca702008-12-10 11:44:30 +0000820** These integer constants can be used as the third parameter to
drhfddfa2d2007-12-05 18:05:16 +0000821** the xAccess method of an [sqlite3_vfs] object. {END} They determine
mihailim04bcc002008-06-22 10:21:27 +0000822** what kind of permissions the xAccess method is looking for.
drh032ca702008-12-10 11:44:30 +0000823** With SQLITE_ACCESS_EXISTS, the xAccess method
mihailim04bcc002008-06-22 10:21:27 +0000824** simply checks whether the file exists.
drh032ca702008-12-10 11:44:30 +0000825** With SQLITE_ACCESS_READWRITE, the xAccess method
mihailim04bcc002008-06-22 10:21:27 +0000826** checks whether the file is both readable and writable.
drh032ca702008-12-10 11:44:30 +0000827** With SQLITE_ACCESS_READ, the xAccess method
mihailim04bcc002008-06-22 10:21:27 +0000828** checks whether the file is readable.
drh50d3f902007-08-27 21:10:36 +0000829*/
danielk1977b4b47412007-08-17 15:53:36 +0000830#define SQLITE_ACCESS_EXISTS 0
831#define SQLITE_ACCESS_READWRITE 1
drh50d3f902007-08-27 21:10:36 +0000832#define SQLITE_ACCESS_READ 2
danielk1977b4b47412007-08-17 15:53:36 +0000833
drh6d2069d2007-08-14 01:58:53 +0000834/*
drhd68eee02009-12-11 03:44:18 +0000835** CAPI3REF: Initialize The SQLite Library
drh673299b2008-06-09 21:57:22 +0000836**
drhd68eee02009-12-11 03:44:18 +0000837** ^The sqlite3_initialize() routine initializes the
838** SQLite library. ^The sqlite3_shutdown() routine
drhcb041342008-06-12 00:07:29 +0000839** deallocates any resources that were allocated by sqlite3_initialize().
drh481aa742009-11-05 18:46:02 +0000840** These routines are designed to aid in process initialization and
drh9524f4b2009-10-20 15:27:55 +0000841** shutdown on embedded systems. Workstation applications using
842** SQLite normally do not need to invoke either of these routines.
drh673299b2008-06-09 21:57:22 +0000843**
drhcb041342008-06-12 00:07:29 +0000844** A call to sqlite3_initialize() is an "effective" call if it is
845** the first time sqlite3_initialize() is invoked during the lifetime of
846** the process, or if it is the first time sqlite3_initialize() is invoked
drhd68eee02009-12-11 03:44:18 +0000847** following a call to sqlite3_shutdown(). ^(Only an effective call
drhcb041342008-06-12 00:07:29 +0000848** of sqlite3_initialize() does any initialization. All other calls
drhd68eee02009-12-11 03:44:18 +0000849** are harmless no-ops.)^
drhcb041342008-06-12 00:07:29 +0000850**
drhd1a24402009-04-19 12:23:58 +0000851** A call to sqlite3_shutdown() is an "effective" call if it is the first
drhd68eee02009-12-11 03:44:18 +0000852** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
drhd1a24402009-04-19 12:23:58 +0000853** an effective call to sqlite3_shutdown() does any deinitialization.
drhd68eee02009-12-11 03:44:18 +0000854** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
drhd1a24402009-04-19 12:23:58 +0000855**
drh9524f4b2009-10-20 15:27:55 +0000856** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
857** is not. The sqlite3_shutdown() interface must only be called from a
858** single thread. All open [database connections] must be closed and all
859** other SQLite resources must be deallocated prior to invoking
860** sqlite3_shutdown().
861**
drhd68eee02009-12-11 03:44:18 +0000862** Among other things, ^sqlite3_initialize() will invoke
863** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
drh9524f4b2009-10-20 15:27:55 +0000864** will invoke sqlite3_os_end().
drh673299b2008-06-09 21:57:22 +0000865**
drhd68eee02009-12-11 03:44:18 +0000866** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
867** ^If for some reason, sqlite3_initialize() is unable to initialize
drhce5a5a02008-06-10 17:41:44 +0000868** the library (perhaps it is unable to allocate a needed resource such
drhadfae6c2008-10-10 17:26:35 +0000869** as a mutex) it returns an [error code] other than [SQLITE_OK].
drh673299b2008-06-09 21:57:22 +0000870**
drhd68eee02009-12-11 03:44:18 +0000871** ^The sqlite3_initialize() routine is called internally by many other
drhcb041342008-06-12 00:07:29 +0000872** SQLite interfaces so that an application usually does not need to
drhce5a5a02008-06-10 17:41:44 +0000873** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
874** calls sqlite3_initialize() so the SQLite library will be automatically
875** initialized when [sqlite3_open()] is called if it has not be initialized
drhd68eee02009-12-11 03:44:18 +0000876** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
drhcb041342008-06-12 00:07:29 +0000877** compile-time option, then the automatic calls to sqlite3_initialize()
878** are omitted and the application must call sqlite3_initialize() directly
879** prior to using any other SQLite interface. For maximum portability,
880** it is recommended that applications always invoke sqlite3_initialize()
881** directly prior to using any other SQLite interface. Future releases
882** of SQLite may require this. In other words, the behavior exhibited
drhadfae6c2008-10-10 17:26:35 +0000883** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
drhcb041342008-06-12 00:07:29 +0000884** default behavior in some future release of SQLite.
drh673299b2008-06-09 21:57:22 +0000885**
drhcb041342008-06-12 00:07:29 +0000886** The sqlite3_os_init() routine does operating-system specific
887** initialization of the SQLite library. The sqlite3_os_end()
888** routine undoes the effect of sqlite3_os_init(). Typical tasks
889** performed by these routines include allocation or deallocation
890** of static resources, initialization of global variables,
891** setting up a default [sqlite3_vfs] module, or setting up
mihailima3f64902008-06-21 13:35:56 +0000892** a default configuration using [sqlite3_config()].
drh673299b2008-06-09 21:57:22 +0000893**
drhcb041342008-06-12 00:07:29 +0000894** The application should never invoke either sqlite3_os_init()
895** or sqlite3_os_end() directly. The application should only invoke
896** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
mihailima3f64902008-06-21 13:35:56 +0000897** interface is called automatically by sqlite3_initialize() and
drhcb041342008-06-12 00:07:29 +0000898** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
899** implementations for sqlite3_os_init() and sqlite3_os_end()
shane7c7c3112009-08-17 15:31:23 +0000900** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
drh6aa5f152009-08-19 15:57:07 +0000901** When [custom builds | built for other platforms]
902** (using the [SQLITE_OS_OTHER=1] compile-time
drhcb041342008-06-12 00:07:29 +0000903** option) the application must supply a suitable implementation for
904** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
905** implementation of sqlite3_os_init() or sqlite3_os_end()
drhadfae6c2008-10-10 17:26:35 +0000906** must return [SQLITE_OK] on success and some other [error code] upon
drhcb041342008-06-12 00:07:29 +0000907** failure.
drh673299b2008-06-09 21:57:22 +0000908*/
drhce5a5a02008-06-10 17:41:44 +0000909int sqlite3_initialize(void);
drh673299b2008-06-09 21:57:22 +0000910int sqlite3_shutdown(void);
drhcb041342008-06-12 00:07:29 +0000911int sqlite3_os_init(void);
912int sqlite3_os_end(void);
drh673299b2008-06-09 21:57:22 +0000913
drhce5a5a02008-06-10 17:41:44 +0000914/*
drhd68eee02009-12-11 03:44:18 +0000915** CAPI3REF: Configuring The SQLite Library
drhd5a68d32008-08-04 13:44:57 +0000916** EXPERIMENTAL
drhce5a5a02008-06-10 17:41:44 +0000917**
918** The sqlite3_config() interface is used to make global configuration
919** changes to SQLite in order to tune SQLite to the specific needs of
920** the application. The default configuration is recommended for most
921** applications and so this routine is usually not necessary. It is
922** provided to support rare applications with unusual needs.
923**
924** The sqlite3_config() interface is not threadsafe. The application
925** must insure that no other SQLite interfaces are invoked by other
926** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
927** may only be invoked prior to library initialization using
928** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
drhd68eee02009-12-11 03:44:18 +0000929** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
930** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
931** Note, however, that ^sqlite3_config() can be called as part of the
drh40257ff2008-06-13 18:24:27 +0000932** implementation of an application-defined [sqlite3_os_init()].
drhce5a5a02008-06-10 17:41:44 +0000933**
934** The first argument to sqlite3_config() is an integer
935** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines
936** what property of SQLite is to be configured. Subsequent arguments
937** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option]
938** in the first argument.
939**
drhd68eee02009-12-11 03:44:18 +0000940** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
941** ^If the option is unknown or SQLite is unable to set the option
drh40257ff2008-06-13 18:24:27 +0000942** then this routine returns a non-zero [error code].
drhce5a5a02008-06-10 17:41:44 +0000943*/
shanea79c3cc2008-08-11 17:27:01 +0000944SQLITE_EXPERIMENTAL int sqlite3_config(int, ...);
drhce5a5a02008-06-10 17:41:44 +0000945
946/*
drhd68eee02009-12-11 03:44:18 +0000947** CAPI3REF: Configure database connections
drhd5a68d32008-08-04 13:44:57 +0000948** EXPERIMENTAL
drh633e6d52008-07-28 19:34:53 +0000949**
950** The sqlite3_db_config() interface is used to make configuration
drh2462e322008-07-31 14:47:54 +0000951** changes to a [database connection]. The interface is similar to
952** [sqlite3_config()] except that the changes apply to a single
953** [database connection] (specified in the first argument). The
drhd68eee02009-12-11 03:44:18 +0000954** sqlite3_db_config() interface should only be used immediately after
drh2462e322008-07-31 14:47:54 +0000955** the database connection is created using [sqlite3_open()],
956** [sqlite3_open16()], or [sqlite3_open_v2()].
957**
958** The second argument to sqlite3_db_config(D,V,...) is the
959** configuration verb - an integer code that indicates what
960** aspect of the [database connection] is being configured.
drhe9d1c722008-08-04 20:13:26 +0000961** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].
drh2462e322008-07-31 14:47:54 +0000962** New verbs are likely to be added in future releases of SQLite.
drhe9d1c722008-08-04 20:13:26 +0000963** Additional arguments depend on the verb.
drhf8cecda2008-10-10 23:48:25 +0000964**
drhd68eee02009-12-11 03:44:18 +0000965** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
966** the call is considered successful.
967**
drh8b39db12009-02-18 18:37:58 +0000968** Requirements:
969** [H14203] [H14206] [H14209] [H14212] [H14215]
drh633e6d52008-07-28 19:34:53 +0000970*/
shanea79c3cc2008-08-11 17:27:01 +0000971SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...);
drh633e6d52008-07-28 19:34:53 +0000972
973/*
drh9cd29642008-07-23 00:52:55 +0000974** CAPI3REF: Memory Allocation Routines {H10155} <S20120>
drhd5a68d32008-08-04 13:44:57 +0000975** EXPERIMENTAL
drhfec00ea2008-06-14 16:56:21 +0000976**
977** An instance of this object defines the interface between SQLite
mihailima3f64902008-06-21 13:35:56 +0000978** and low-level memory allocation routines.
drhfec00ea2008-06-14 16:56:21 +0000979**
980** This object is used in only one place in the SQLite interface.
981** A pointer to an instance of this object is the argument to
drh4766b292008-06-26 02:53:02 +0000982** [sqlite3_config()] when the configuration option is
drh6aa5f152009-08-19 15:57:07 +0000983** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
984** By creating an instance of this object
985** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
986** during configuration, an application can specify an alternative
987** memory allocation subsystem for SQLite to use for all of its
988** dynamic memory needs.
drhfec00ea2008-06-14 16:56:21 +0000989**
drh6aa5f152009-08-19 15:57:07 +0000990** Note that SQLite comes with several [built-in memory allocators]
991** that are perfectly adequate for the overwhelming majority of applications
drhfec00ea2008-06-14 16:56:21 +0000992** and that this object is only useful to a tiny minority of applications
993** with specialized memory allocation requirements. This object is
994** also used during testing of SQLite in order to specify an alternative
995** memory allocator that simulates memory out-of-memory conditions in
996** order to verify that SQLite recovers gracefully from such
997** conditions.
998**
drh6aa5f152009-08-19 15:57:07 +0000999** The xMalloc and xFree methods must work like the
1000** malloc() and free() functions from the standard C library.
1001** The xRealloc method must work like realloc() from the standard C library
1002** with the exception that if the second argument to xRealloc is zero,
1003** xRealloc must be a no-op - it must not perform any allocation or
drhd68eee02009-12-11 03:44:18 +00001004** deallocation. ^SQLite guarantees that the second argument to
drh6aa5f152009-08-19 15:57:07 +00001005** xRealloc is always a value returned by a prior call to xRoundup.
1006** And so in cases where xRoundup always returns a positive number,
1007** xRealloc can perform exactly as the standard library realloc() and
1008** still be in compliance with this specification.
drhfec00ea2008-06-14 16:56:21 +00001009**
1010** xSize should return the allocated size of a memory allocation
1011** previously obtained from xMalloc or xRealloc. The allocated size
1012** is always at least as big as the requested size but may be larger.
1013**
1014** The xRoundup method returns what would be the allocated size of
1015** a memory allocation given a particular requested size. Most memory
1016** allocators round up memory allocations at least to the next multiple
mihailima3f64902008-06-21 13:35:56 +00001017** of 8. Some allocators round up to a larger multiple or to a power of 2.
drh6aa5f152009-08-19 15:57:07 +00001018** Every memory allocation request coming in through [sqlite3_malloc()]
1019** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1020** that causes the corresponding memory allocation to fail.
drhe5ae5732008-06-15 02:51:47 +00001021**
drhfec00ea2008-06-14 16:56:21 +00001022** The xInit method initializes the memory allocator. (For example,
1023** it might allocate any require mutexes or initialize internal data
1024** structures. The xShutdown method is invoked (indirectly) by
1025** [sqlite3_shutdown()] and should deallocate any resources acquired
1026** by xInit. The pAppData pointer is used as the only parameter to
1027** xInit and xShutdown.
drh9ac06502009-08-17 13:42:29 +00001028**
1029** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1030** the xInit method, so the xInit method need not be threadsafe. The
1031** xShutdown method is only called from [sqlite3_shutdown()] so it does
drh6aa5f152009-08-19 15:57:07 +00001032** not need to be threadsafe either. For all other methods, SQLite
1033** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1034** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1035** it is by default) and so the methods are automatically serialized.
1036** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1037** methods must be threadsafe or else make their own arrangements for
1038** serialization.
drh9ac06502009-08-17 13:42:29 +00001039**
1040** SQLite will never invoke xInit() more than once without an intervening
1041** call to xShutdown().
drhfec00ea2008-06-14 16:56:21 +00001042*/
1043typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1044struct sqlite3_mem_methods {
1045 void *(*xMalloc)(int); /* Memory allocation function */
1046 void (*xFree)(void*); /* Free a prior allocation */
1047 void *(*xRealloc)(void*,int); /* Resize an allocation */
1048 int (*xSize)(void*); /* Return the size of an allocation */
1049 int (*xRoundup)(int); /* Round up request size to allocation size */
1050 int (*xInit)(void*); /* Initialize the memory allocator */
1051 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1052 void *pAppData; /* Argument to xInit() and xShutdown() */
1053};
1054
1055/*
drh9cd29642008-07-23 00:52:55 +00001056** CAPI3REF: Configuration Options {H10160} <S20000>
drhd5a68d32008-08-04 13:44:57 +00001057** EXPERIMENTAL
drhce5a5a02008-06-10 17:41:44 +00001058**
1059** These constants are the available integer configuration options that
1060** can be passed as the first argument to the [sqlite3_config()] interface.
mihailima3f64902008-06-21 13:35:56 +00001061**
drha911abe2008-07-16 13:29:51 +00001062** New configuration options may be added in future releases of SQLite.
1063** Existing configuration options might be discontinued. Applications
1064** should check the return code from [sqlite3_config()] to make sure that
1065** the call worked. The [sqlite3_config()] interface will return a
1066** non-zero [error code] if a discontinued or unsupported configuration option
1067** is invoked.
1068**
drhce5a5a02008-06-10 17:41:44 +00001069** <dl>
1070** <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
drhd68eee02009-12-11 03:44:18 +00001071** <dd>There are no arguments to this option. ^This option sets the
1072** [threading mode] to Single-thread. In other words, it disables
drhce5a5a02008-06-10 17:41:44 +00001073** all mutexing and puts SQLite into a mode where it can only be used
drhd68eee02009-12-11 03:44:18 +00001074** by a single thread. ^If SQLite is compiled with
1075** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1076** it is not possible to change the [threading mode] from its default
1077** value of Single-thread and so [sqlite3_config()] will return
1078** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1079** configuration option.</dd>
drhce5a5a02008-06-10 17:41:44 +00001080**
1081** <dt>SQLITE_CONFIG_MULTITHREAD</dt>
drhd68eee02009-12-11 03:44:18 +00001082** <dd>There are no arguments to this option. ^This option sets the
1083** [threading mode] to Multi-thread. In other words, it disables
drhce5a5a02008-06-10 17:41:44 +00001084** mutexing on [database connection] and [prepared statement] objects.
1085** The application is responsible for serializing access to
1086** [database connections] and [prepared statements]. But other mutexes
1087** are enabled so that SQLite will be safe to use in a multi-threaded
drhafacce02008-09-02 21:35:03 +00001088** environment as long as no two threads attempt to use the same
drhd68eee02009-12-11 03:44:18 +00001089** [database connection] at the same time. ^If SQLite is compiled with
1090** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1091** it is not possible to set the Multi-thread [threading mode] and
1092** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1093** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
drhce5a5a02008-06-10 17:41:44 +00001094**
1095** <dt>SQLITE_CONFIG_SERIALIZED</dt>
drhd68eee02009-12-11 03:44:18 +00001096** <dd>There are no arguments to this option. ^This option sets the
1097** [threading mode] to Serialized. In other words, this option enables
drhce5a5a02008-06-10 17:41:44 +00001098** all mutexes including the recursive
1099** mutexes on [database connection] and [prepared statement] objects.
1100** In this mode (which is the default when SQLite is compiled with
drh4766b292008-06-26 02:53:02 +00001101** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
drhce5a5a02008-06-10 17:41:44 +00001102** to [database connections] and [prepared statements] so that the
1103** application is free to use the same [database connection] or the
drh31d38cf2008-07-12 20:35:08 +00001104** same [prepared statement] in different threads at the same time.
drhd68eee02009-12-11 03:44:18 +00001105** ^If SQLite is compiled with
1106** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1107** it is not possible to set the Serialized [threading mode] and
1108** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1109** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
drhce5a5a02008-06-10 17:41:44 +00001110**
1111** <dt>SQLITE_CONFIG_MALLOC</dt>
drhd68eee02009-12-11 03:44:18 +00001112** <dd> ^(This option takes a single argument which is a pointer to an
mihailimdb4f2ad2008-06-21 11:20:48 +00001113** instance of the [sqlite3_mem_methods] structure. The argument specifies
1114** alternative low-level memory allocation routines to be used in place of
drhd68eee02009-12-11 03:44:18 +00001115** the memory allocation routines built into SQLite.)^ ^SQLite makes
1116** its own private copy of the content of the [sqlite3_mem_methods] structure
1117** before the [sqlite3_config()] call returns.</dd>
drhce5a5a02008-06-10 17:41:44 +00001118**
drh33589792008-06-18 13:27:46 +00001119** <dt>SQLITE_CONFIG_GETMALLOC</dt>
drhd68eee02009-12-11 03:44:18 +00001120** <dd> ^(This option takes a single argument which is a pointer to an
drh33589792008-06-18 13:27:46 +00001121** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
drhd68eee02009-12-11 03:44:18 +00001122** structure is filled with the currently defined memory allocation routines.)^
drh33589792008-06-18 13:27:46 +00001123** This option can be used to overload the default memory allocation
1124** routines with a wrapper that simulations memory allocation failure or
drhd68eee02009-12-11 03:44:18 +00001125** tracks memory usage, for example. </dd>
drh33589792008-06-18 13:27:46 +00001126**
drhfec00ea2008-06-14 16:56:21 +00001127** <dt>SQLITE_CONFIG_MEMSTATUS</dt>
drhd68eee02009-12-11 03:44:18 +00001128** <dd> ^This option takes single argument of type int, interpreted as a
danielk197795c232d2008-07-28 05:22:35 +00001129** boolean, which enables or disables the collection of memory allocation
drhd68eee02009-12-11 03:44:18 +00001130** statistics. ^(When memory allocation statistics are disabled, the
1131** following SQLite interfaces become non-operational:
drhce5a5a02008-06-10 17:41:44 +00001132** <ul>
1133** <li> [sqlite3_memory_used()]
1134** <li> [sqlite3_memory_highwater()]
1135** <li> [sqlite3_soft_heap_limit()]
drh0a60a382008-07-31 17:16:05 +00001136** <li> [sqlite3_status()]
drhd68eee02009-12-11 03:44:18 +00001137** </ul>)^
1138** ^Memory allocation statistics are enabled by default unless SQLite is
1139** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1140** allocation statistics are disabled by default.
drhce5a5a02008-06-10 17:41:44 +00001141** </dd>
drh33589792008-06-18 13:27:46 +00001142**
1143** <dt>SQLITE_CONFIG_SCRATCH</dt>
drhd68eee02009-12-11 03:44:18 +00001144** <dd> ^This option specifies a static memory buffer that SQLite can use for
drh6860da02009-06-09 19:53:58 +00001145** scratch memory. There are three arguments: A pointer an 8-byte
1146** aligned memory buffer from which the scrach allocations will be
1147** drawn, the size of each scratch allocation (sz),
1148** and the maximum number of scratch allocations (N). The sz
drh0a60a382008-07-31 17:16:05 +00001149** argument must be a multiple of 16. The sz parameter should be a few bytes
drh6860da02009-06-09 19:53:58 +00001150** larger than the actual scratch space required due to internal overhead.
drhd68eee02009-12-11 03:44:18 +00001151** The first argument must be a pointer to an 8-byte aligned buffer
drh6860da02009-06-09 19:53:58 +00001152** of at least sz*N bytes of memory.
drhd68eee02009-12-11 03:44:18 +00001153** ^SQLite will use no more than one scratch buffer per thread. So
1154** N should be set to the expected maximum number of threads. ^SQLite will
1155** never require a scratch buffer that is more than 6 times the database
1156** page size. ^If SQLite needs needs additional scratch memory beyond
1157** what is provided by this configuration option, then
1158** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
drh33589792008-06-18 13:27:46 +00001159**
1160** <dt>SQLITE_CONFIG_PAGECACHE</dt>
drhd68eee02009-12-11 03:44:18 +00001161** <dd> ^This option specifies a static memory buffer that SQLite can use for
drh21614742008-11-18 19:18:08 +00001162** the database page cache with the default page cache implemenation.
1163** This configuration should not be used if an application-define page
1164** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
drh6860da02009-06-09 19:53:58 +00001165** There are three arguments to this option: A pointer to 8-byte aligned
mihailimdb4f2ad2008-06-21 11:20:48 +00001166** memory, the size of each page buffer (sz), and the number of pages (N).
drh6860da02009-06-09 19:53:58 +00001167** The sz argument should be the size of the largest database page
1168** (a power of two between 512 and 32768) plus a little extra for each
drhd68eee02009-12-11 03:44:18 +00001169** page header. ^The page header size is 20 to 40 bytes depending on
1170** the host architecture. ^It is harmless, apart from the wasted memory,
drh6860da02009-06-09 19:53:58 +00001171** to make sz a little too large. The first
drh0a60a382008-07-31 17:16:05 +00001172** argument should point to an allocation of at least sz*N bytes of memory.
drhd68eee02009-12-11 03:44:18 +00001173** ^SQLite will use the memory provided by the first argument to satisfy its
1174** memory needs for the first N pages that it adds to cache. ^If additional
mihailimdb4f2ad2008-06-21 11:20:48 +00001175** page cache memory is needed beyond what is provided by this option, then
drh0a60a382008-07-31 17:16:05 +00001176** SQLite goes to [sqlite3_malloc()] for the additional storage space.
drhd68eee02009-12-11 03:44:18 +00001177** ^The implementation might use one or more of the N buffers to hold
drh6860da02009-06-09 19:53:58 +00001178** memory accounting information. The pointer in the first argument must
1179** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1180** will be undefined.</dd>
drh33589792008-06-18 13:27:46 +00001181**
1182** <dt>SQLITE_CONFIG_HEAP</dt>
drhd68eee02009-12-11 03:44:18 +00001183** <dd> ^This option specifies a static memory buffer that SQLite will use
drh33589792008-06-18 13:27:46 +00001184** for all of its dynamic memory allocation needs beyond those provided
1185** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
drh6860da02009-06-09 19:53:58 +00001186** There are three arguments: An 8-byte aligned pointer to the memory,
1187** the number of bytes in the memory buffer, and the minimum allocation size.
drhd68eee02009-12-11 03:44:18 +00001188** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
drh8a42cbd2008-07-10 18:13:42 +00001189** to using its default memory allocator (the system malloc() implementation),
drhd68eee02009-12-11 03:44:18 +00001190** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
drh8a42cbd2008-07-10 18:13:42 +00001191** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1192** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
drh39bf74a2009-06-09 18:02:10 +00001193** allocator is engaged to handle all of SQLites memory allocation needs.
1194** The first pointer (the memory pointer) must be aligned to an 8-byte
drh6860da02009-06-09 19:53:58 +00001195** boundary or subsequent behavior of SQLite will be undefined.</dd>
drh33589792008-06-18 13:27:46 +00001196**
1197** <dt>SQLITE_CONFIG_MUTEX</dt>
drhd68eee02009-12-11 03:44:18 +00001198** <dd> ^(This option takes a single argument which is a pointer to an
mihailimdb4f2ad2008-06-21 11:20:48 +00001199** instance of the [sqlite3_mutex_methods] structure. The argument specifies
drh33589792008-06-18 13:27:46 +00001200** alternative low-level mutex routines to be used in place
drhd68eee02009-12-11 03:44:18 +00001201** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
1202** content of the [sqlite3_mutex_methods] structure before the call to
1203** [sqlite3_config()] returns. ^If SQLite is compiled with
1204** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1205** the entire mutexing subsystem is omitted from the build and hence calls to
1206** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1207** return [SQLITE_ERROR].</dd>
drh33589792008-06-18 13:27:46 +00001208**
drh584ff182008-07-14 18:38:17 +00001209** <dt>SQLITE_CONFIG_GETMUTEX</dt>
drhd68eee02009-12-11 03:44:18 +00001210** <dd> ^(This option takes a single argument which is a pointer to an
drh33589792008-06-18 13:27:46 +00001211** instance of the [sqlite3_mutex_methods] structure. The
1212** [sqlite3_mutex_methods]
drhd68eee02009-12-11 03:44:18 +00001213** structure is filled with the currently defined mutex routines.)^
drh33589792008-06-18 13:27:46 +00001214** This option can be used to overload the default mutex allocation
1215** routines with a wrapper used to track mutex usage for performance
drhd68eee02009-12-11 03:44:18 +00001216** profiling or testing, for example. ^If SQLite is compiled with
1217** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1218** the entire mutexing subsystem is omitted from the build and hence calls to
1219** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1220** return [SQLITE_ERROR].</dd>
drh633e6d52008-07-28 19:34:53 +00001221**
1222** <dt>SQLITE_CONFIG_LOOKASIDE</dt>
drhd68eee02009-12-11 03:44:18 +00001223** <dd> ^(This option takes two arguments that determine the default
drh6aa5f152009-08-19 15:57:07 +00001224** memory allocation lookaside optimization. The first argument is the
drh633e6d52008-07-28 19:34:53 +00001225** size of each lookaside buffer slot and the second is the number of
drhd68eee02009-12-11 03:44:18 +00001226** slots allocated to each database connection.)^ ^(This option sets the
1227** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
drh6aa5f152009-08-19 15:57:07 +00001228** verb to [sqlite3_db_config()] can be used to change the lookaside
drhd68eee02009-12-11 03:44:18 +00001229** configuration on individual connections.)^ </dd>
drh633e6d52008-07-28 19:34:53 +00001230**
drh21614742008-11-18 19:18:08 +00001231** <dt>SQLITE_CONFIG_PCACHE</dt>
drhd68eee02009-12-11 03:44:18 +00001232** <dd> ^(This option takes a single argument which is a pointer to
drh21614742008-11-18 19:18:08 +00001233** an [sqlite3_pcache_methods] object. This object specifies the interface
drhd68eee02009-12-11 03:44:18 +00001234** to a custom page cache implementation.)^ ^SQLite makes a copy of the
drh21614742008-11-18 19:18:08 +00001235** object and uses it for page cache memory allocations.</dd>
1236**
1237** <dt>SQLITE_CONFIG_GETPCACHE</dt>
drhd68eee02009-12-11 03:44:18 +00001238** <dd> ^(This option takes a single argument which is a pointer to an
drh21614742008-11-18 19:18:08 +00001239** [sqlite3_pcache_methods] object. SQLite copies of the current
drhd68eee02009-12-11 03:44:18 +00001240** page cache implementation into that object.)^ </dd>
drh21614742008-11-18 19:18:08 +00001241**
drh633e6d52008-07-28 19:34:53 +00001242** </dl>
mihailima3f64902008-06-21 13:35:56 +00001243*/
drh40257ff2008-06-13 18:24:27 +00001244#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1245#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1246#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
drhfec00ea2008-06-14 16:56:21 +00001247#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
drh33589792008-06-18 13:27:46 +00001248#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1249#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1250#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1251#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1252#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1253#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1254#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
shane2479de32008-11-10 18:05:35 +00001255/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
drh633e6d52008-07-28 19:34:53 +00001256#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
danielk1977bc2ca9e2008-11-13 14:28:28 +00001257#define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */
1258#define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */
danielk19772d340812008-07-24 08:20:40 +00001259
drhe9d1c722008-08-04 20:13:26 +00001260/*
1261** CAPI3REF: Configuration Options {H10170} <S20000>
1262** EXPERIMENTAL
1263**
1264** These constants are the available integer configuration options that
1265** can be passed as the second argument to the [sqlite3_db_config()] interface.
1266**
1267** New configuration options may be added in future releases of SQLite.
1268** Existing configuration options might be discontinued. Applications
1269** should check the return code from [sqlite3_db_config()] to make sure that
drhd68eee02009-12-11 03:44:18 +00001270** the call worked. ^The [sqlite3_db_config()] interface will return a
drhe9d1c722008-08-04 20:13:26 +00001271** non-zero [error code] if a discontinued or unsupported configuration option
1272** is invoked.
1273**
1274** <dl>
1275** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
drhd68eee02009-12-11 03:44:18 +00001276** <dd> ^This option takes three additional arguments that determine the
drhe9d1c722008-08-04 20:13:26 +00001277** [lookaside memory allocator] configuration for the [database connection].
drhd68eee02009-12-11 03:44:18 +00001278** ^The first argument (the third parameter to [sqlite3_db_config()] is a
drh6aa5f152009-08-19 15:57:07 +00001279** pointer to an memory buffer to use for lookaside memory.
drhd68eee02009-12-11 03:44:18 +00001280** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1281** may be NULL in which case SQLite will allocate the
1282** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1283** size of each lookaside buffer slot. ^The third argument is the number of
drhe9d1c722008-08-04 20:13:26 +00001284** slots. The size of the buffer in the first argument must be greater than
drh6aa5f152009-08-19 15:57:07 +00001285** or equal to the product of the second and third arguments. The buffer
drhd68eee02009-12-11 03:44:18 +00001286** must be aligned to an 8-byte boundary. ^If the second argument to
1287** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1288** rounded down to the next smaller
drh6aa5f152009-08-19 15:57:07 +00001289** multiple of 8. See also: [SQLITE_CONFIG_LOOKASIDE]</dd>
drhe9d1c722008-08-04 20:13:26 +00001290**
1291** </dl>
1292*/
1293#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1294
drhce5a5a02008-06-10 17:41:44 +00001295
drh673299b2008-06-09 21:57:22 +00001296/*
drhd68eee02009-12-11 03:44:18 +00001297** CAPI3REF: Enable Or Disable Extended Result Codes
drh6ed48bf2007-06-14 20:57:18 +00001298**
drhd68eee02009-12-11 03:44:18 +00001299** ^The sqlite3_extended_result_codes() routine enables or disables the
1300** [extended result codes] feature of SQLite. ^The extended result
1301** codes are disabled by default for historical compatibility.
drh4ac285a2006-09-15 07:28:50 +00001302*/
1303int sqlite3_extended_result_codes(sqlite3*, int onoff);
1304
1305/*
drhd68eee02009-12-11 03:44:18 +00001306** CAPI3REF: Last Insert Rowid
drh6ed48bf2007-06-14 20:57:18 +00001307**
drhd68eee02009-12-11 03:44:18 +00001308** ^Each entry in an SQLite table has a unique 64-bit signed
1309** integer key called the [ROWID | "rowid"]. ^The rowid is always available
drhfddfa2d2007-12-05 18:05:16 +00001310** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
drhd68eee02009-12-11 03:44:18 +00001311** names are not also used by explicitly declared columns. ^If
drh49c3d572008-12-15 22:51:38 +00001312** the table has a column of type [INTEGER PRIMARY KEY] then that column
mlcreechb2799412008-03-07 03:20:31 +00001313** is another alias for the rowid.
drh6ed48bf2007-06-14 20:57:18 +00001314**
drhd68eee02009-12-11 03:44:18 +00001315** ^This routine returns the [rowid] of the most recent
drhf8cecda2008-10-10 23:48:25 +00001316** successful [INSERT] into the database from the [database connection]
drhd68eee02009-12-11 03:44:18 +00001317** in the first argument. ^If no successful [INSERT]s
mihailimdb4f2ad2008-06-21 11:20:48 +00001318** have ever occurred on that database connection, zero is returned.
drh6ed48bf2007-06-14 20:57:18 +00001319**
drhd68eee02009-12-11 03:44:18 +00001320** ^(If an [INSERT] occurs within a trigger, then the [rowid] of the inserted
mihailimdb4f2ad2008-06-21 11:20:48 +00001321** row is returned by this routine as long as the trigger is running.
1322** But once the trigger terminates, the value returned by this routine
drhd68eee02009-12-11 03:44:18 +00001323** reverts to the last value inserted before the trigger fired.)^
drhe30f4422007-08-21 16:15:55 +00001324**
drhd68eee02009-12-11 03:44:18 +00001325** ^An [INSERT] that fails due to a constraint violation is not a
drhf8cecda2008-10-10 23:48:25 +00001326** successful [INSERT] and does not change the value returned by this
drhd68eee02009-12-11 03:44:18 +00001327** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
drhdc1d9f12007-10-27 16:25:16 +00001328** and INSERT OR ABORT make no changes to the return value of this
drhd68eee02009-12-11 03:44:18 +00001329** routine when their insertion fails. ^(When INSERT OR REPLACE
drhdc1d9f12007-10-27 16:25:16 +00001330** encounters a constraint violation, it does not fail. The
1331** INSERT continues to completion after deleting rows that caused
1332** the constraint problem so INSERT OR REPLACE will always change
drhd68eee02009-12-11 03:44:18 +00001333** the return value of this interface.)^
drhdc1d9f12007-10-27 16:25:16 +00001334**
drhd68eee02009-12-11 03:44:18 +00001335** ^For the purposes of this routine, an [INSERT] is considered to
drh33c1be32008-01-30 16:16:14 +00001336** be successful even if it is subsequently rolled back.
1337**
drha94cc422009-12-03 01:01:02 +00001338** This function is accessible to SQL statements via the
1339** [last_insert_rowid() SQL function].
1340**
drh8b39db12009-02-18 18:37:58 +00001341** If a separate thread performs a new [INSERT] on the same
1342** database connection while the [sqlite3_last_insert_rowid()]
1343** function is running and thus changes the last insert [rowid],
1344** then the value returned by [sqlite3_last_insert_rowid()] is
1345** unpredictable and might not equal either the old or the new
1346** last insert [rowid].
drhaf9ff332002-01-16 21:00:27 +00001347*/
drh6d2069d2007-08-14 01:58:53 +00001348sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
drhaf9ff332002-01-16 21:00:27 +00001349
drhc8d30ac2002-04-12 10:08:59 +00001350/*
drhd68eee02009-12-11 03:44:18 +00001351** CAPI3REF: Count The Number Of Rows Modified
drh6ed48bf2007-06-14 20:57:18 +00001352**
drhd68eee02009-12-11 03:44:18 +00001353** ^This function returns the number of database rows that were changed
drhfddfa2d2007-12-05 18:05:16 +00001354** or inserted or deleted by the most recently completed SQL statement
mihailimdb4f2ad2008-06-21 11:20:48 +00001355** on the [database connection] specified by the first parameter.
drhd68eee02009-12-11 03:44:18 +00001356** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
drhf8cecda2008-10-10 23:48:25 +00001357** or [DELETE] statement are counted. Auxiliary changes caused by
drhd68eee02009-12-11 03:44:18 +00001358** triggers or [foreign key actions] are not counted.)^ Use the
danb6163092009-10-07 10:43:26 +00001359** [sqlite3_total_changes()] function to find the total number of changes
1360** including changes caused by triggers and foreign key actions.
drh6ed48bf2007-06-14 20:57:18 +00001361**
drhd68eee02009-12-11 03:44:18 +00001362** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
drhd9c20d72009-04-29 14:33:44 +00001363** are not counted. Only real table changes are counted.
1364**
drhd68eee02009-12-11 03:44:18 +00001365** ^(A "row change" is a change to a single row of a single table
drh33c1be32008-01-30 16:16:14 +00001366** caused by an INSERT, DELETE, or UPDATE statement. Rows that
drhd9c20d72009-04-29 14:33:44 +00001367** are changed as side effects of [REPLACE] constraint resolution,
1368** rollback, ABORT processing, [DROP TABLE], or by any other
drhd68eee02009-12-11 03:44:18 +00001369** mechanisms do not count as direct row changes.)^
drh33c1be32008-01-30 16:16:14 +00001370**
1371** A "trigger context" is a scope of execution that begins and
drhd9c20d72009-04-29 14:33:44 +00001372** ends with the script of a [CREATE TRIGGER | trigger].
1373** Most SQL statements are
drh33c1be32008-01-30 16:16:14 +00001374** evaluated outside of any trigger. This is the "top level"
1375** trigger context. If a trigger fires from the top level, a
1376** new trigger context is entered for the duration of that one
1377** trigger. Subtriggers create subcontexts for their duration.
1378**
drhd68eee02009-12-11 03:44:18 +00001379** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
drh33c1be32008-01-30 16:16:14 +00001380** not create a new trigger context.
1381**
drhd68eee02009-12-11 03:44:18 +00001382** ^This function returns the number of direct row changes in the
drh33c1be32008-01-30 16:16:14 +00001383** most recent INSERT, UPDATE, or DELETE statement within the same
1384** trigger context.
1385**
drhd68eee02009-12-11 03:44:18 +00001386** ^Thus, when called from the top level, this function returns the
drh33c1be32008-01-30 16:16:14 +00001387** number of changes in the most recent INSERT, UPDATE, or DELETE
drhd68eee02009-12-11 03:44:18 +00001388** that also occurred at the top level. ^(Within the body of a trigger,
mihailimdb4f2ad2008-06-21 11:20:48 +00001389** the sqlite3_changes() interface can be called to find the number of
drh930cc582007-03-28 13:07:40 +00001390** changes in the most recently completed INSERT, UPDATE, or DELETE
drhf5befa02007-12-06 02:42:07 +00001391** statement within the body of the same trigger.
mihailimdb4f2ad2008-06-21 11:20:48 +00001392** However, the number returned does not include changes
drhd68eee02009-12-11 03:44:18 +00001393** caused by subtriggers since those have their own context.)^
drhc8d30ac2002-04-12 10:08:59 +00001394**
drha94cc422009-12-03 01:01:02 +00001395** See also the [sqlite3_total_changes()] interface, the
1396** [count_changes pragma], and the [changes() SQL function].
drhe30f4422007-08-21 16:15:55 +00001397**
drh8b39db12009-02-18 18:37:58 +00001398** If a separate thread makes changes on the same database connection
1399** while [sqlite3_changes()] is running then the value returned
1400** is unpredictable and not meaningful.
drhc8d30ac2002-04-12 10:08:59 +00001401*/
danielk1977f9d64d22004-06-19 08:18:07 +00001402int sqlite3_changes(sqlite3*);
drhc8d30ac2002-04-12 10:08:59 +00001403
rdcf146a772004-02-25 22:51:06 +00001404/*
drhd68eee02009-12-11 03:44:18 +00001405** CAPI3REF: Total Number Of Rows Modified
mihailimdb4f2ad2008-06-21 11:20:48 +00001406**
drhd68eee02009-12-11 03:44:18 +00001407** ^This function returns the number of row changes caused by [INSERT],
drhd9c20d72009-04-29 14:33:44 +00001408** [UPDATE] or [DELETE] statements since the [database connection] was opened.
drhd68eee02009-12-11 03:44:18 +00001409** ^(The count returned by sqlite3_total_changes() includes all changes
1410** from all [CREATE TRIGGER | trigger] contexts and changes made by
1411** [foreign key actions]. However,
drhd9c20d72009-04-29 14:33:44 +00001412** the count does not include changes used to implement [REPLACE] constraints,
1413** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
drh4fb08662009-05-22 01:02:26 +00001414** count does not include rows of views that fire an [INSTEAD OF trigger],
1415** though if the INSTEAD OF trigger makes changes of its own, those changes
drhd68eee02009-12-11 03:44:18 +00001416** are counted.)^
1417** ^The sqlite3_total_changes() function counts the changes as soon as
1418** the statement that makes them is completed (when the statement handle
1419** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
drh6ed48bf2007-06-14 20:57:18 +00001420**
drha94cc422009-12-03 01:01:02 +00001421** See also the [sqlite3_changes()] interface, the
1422** [count_changes pragma], and the [total_changes() SQL function].
drh33c1be32008-01-30 16:16:14 +00001423**
drh8b39db12009-02-18 18:37:58 +00001424** If a separate thread makes changes on the same database connection
1425** while [sqlite3_total_changes()] is running then the value
1426** returned is unpredictable and not meaningful.
rdcf146a772004-02-25 22:51:06 +00001427*/
danielk1977b28af712004-06-21 06:50:26 +00001428int sqlite3_total_changes(sqlite3*);
1429
drh6ed48bf2007-06-14 20:57:18 +00001430/*
drhd68eee02009-12-11 03:44:18 +00001431** CAPI3REF: Interrupt A Long-Running Query
drh6ed48bf2007-06-14 20:57:18 +00001432**
drhd68eee02009-12-11 03:44:18 +00001433** ^This function causes any pending database operation to abort and
drh33c1be32008-01-30 16:16:14 +00001434** return at its earliest opportunity. This routine is typically
mihailimebe796c2008-06-21 20:11:17 +00001435** called in response to a user action such as pressing "Cancel"
drh4c504392000-10-16 22:06:40 +00001436** or Ctrl-C where the user wants a long query operation to halt
1437** immediately.
drh930cc582007-03-28 13:07:40 +00001438**
drhd68eee02009-12-11 03:44:18 +00001439** ^It is safe to call this routine from a thread different from the
drh33c1be32008-01-30 16:16:14 +00001440** thread that is currently running the database operation. But it
mihailimdb4f2ad2008-06-21 11:20:48 +00001441** is not safe to call this routine with a [database connection] that
drh871f6ca2007-08-14 18:03:14 +00001442** is closed or might close before sqlite3_interrupt() returns.
drh6ed48bf2007-06-14 20:57:18 +00001443**
drhd68eee02009-12-11 03:44:18 +00001444** ^If an SQL operation is very nearly finished at the time when
mihailimdb4f2ad2008-06-21 11:20:48 +00001445** sqlite3_interrupt() is called, then it might not have an opportunity
1446** to be interrupted and might continue to completion.
1447**
drhd68eee02009-12-11 03:44:18 +00001448** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1449** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
mihailimdb4f2ad2008-06-21 11:20:48 +00001450** that is inside an explicit transaction, then the entire transaction
1451** will be rolled back automatically.
1452**
drhd68eee02009-12-11 03:44:18 +00001453** ^(The sqlite3_interrupt(D) call is in effect until all currently running
drhd2b68432009-04-20 12:31:46 +00001454** SQL statements on [database connection] D complete. Any new SQL statements
1455** that are started after the sqlite3_interrupt() call and before the
1456** running statements reaches zero are interrupted as if they had been
1457** running prior to the sqlite3_interrupt() call. New SQL statements
1458** that are started after the running statement count reaches zero are
drhd68eee02009-12-11 03:44:18 +00001459** not effected by the sqlite3_interrupt().)^
1460** ^A call to sqlite3_interrupt(D) that occurs when there are no running
drhd2b68432009-04-20 12:31:46 +00001461** SQL statements is a no-op and has no effect on SQL statements
1462** that are started after the sqlite3_interrupt() call returns.
drh33c1be32008-01-30 16:16:14 +00001463**
drh8b39db12009-02-18 18:37:58 +00001464** If the database connection closes while [sqlite3_interrupt()]
1465** is running then bad things will likely happen.
drh4c504392000-10-16 22:06:40 +00001466*/
danielk1977f9d64d22004-06-19 08:18:07 +00001467void sqlite3_interrupt(sqlite3*);
drh4c504392000-10-16 22:06:40 +00001468
drh6ed48bf2007-06-14 20:57:18 +00001469/*
drhd68eee02009-12-11 03:44:18 +00001470** CAPI3REF: Determine If An SQL Statement Is Complete
drh75897232000-05-29 14:26:00 +00001471**
drh709915d2009-04-28 04:46:41 +00001472** These routines are useful during command-line input to determine if the
1473** currently entered text seems to form a complete SQL statement or
drhf5befa02007-12-06 02:42:07 +00001474** if additional input is needed before sending the text into
drhd68eee02009-12-11 03:44:18 +00001475** SQLite for parsing. ^These routines return 1 if the input string
1476** appears to be a complete SQL statement. ^A statement is judged to be
drh709915d2009-04-28 04:46:41 +00001477** complete if it ends with a semicolon token and is not a prefix of a
drhd68eee02009-12-11 03:44:18 +00001478** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
drh33c1be32008-01-30 16:16:14 +00001479** string literals or quoted identifier names or comments are not
1480** independent tokens (they are part of the token in which they are
drhd68eee02009-12-11 03:44:18 +00001481** embedded) and thus do not count as a statement terminator. ^Whitespace
drh709915d2009-04-28 04:46:41 +00001482** and comments that follow the final semicolon are ignored.
1483**
drhd68eee02009-12-11 03:44:18 +00001484** ^These routines return 0 if the statement is incomplete. ^If a
drh709915d2009-04-28 04:46:41 +00001485** memory allocation fails, then SQLITE_NOMEM is returned.
drh33c1be32008-01-30 16:16:14 +00001486**
drhd68eee02009-12-11 03:44:18 +00001487** ^These routines do not parse the SQL statements thus
mihailimdb4f2ad2008-06-21 11:20:48 +00001488** will not detect syntactically incorrect SQL.
drhfddfa2d2007-12-05 18:05:16 +00001489**
drhd68eee02009-12-11 03:44:18 +00001490** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
drh709915d2009-04-28 04:46:41 +00001491** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
1492** automatically by sqlite3_complete16(). If that initialization fails,
1493** then the return value from sqlite3_complete16() will be non-zero
drhd68eee02009-12-11 03:44:18 +00001494** regardless of whether or not the input SQL is complete.)^
drh33c1be32008-01-30 16:16:14 +00001495**
drh8b39db12009-02-18 18:37:58 +00001496** The input to [sqlite3_complete()] must be a zero-terminated
1497** UTF-8 string.
drh33c1be32008-01-30 16:16:14 +00001498**
drh8b39db12009-02-18 18:37:58 +00001499** The input to [sqlite3_complete16()] must be a zero-terminated
1500** UTF-16 string in native byte order.
drh75897232000-05-29 14:26:00 +00001501*/
danielk19776f8a5032004-05-10 10:34:51 +00001502int sqlite3_complete(const char *sql);
danielk197761de0d12004-05-27 23:56:16 +00001503int sqlite3_complete16(const void *sql);
drh75897232000-05-29 14:26:00 +00001504
drh2dfbbca2000-07-28 14:32:48 +00001505/*
drhd68eee02009-12-11 03:44:18 +00001506** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
drh6ed48bf2007-06-14 20:57:18 +00001507**
drhd68eee02009-12-11 03:44:18 +00001508** ^This routine sets a callback function that might be invoked whenever
mihailimdb4f2ad2008-06-21 11:20:48 +00001509** an attempt is made to open a database table that another thread
1510** or process has locked.
1511**
drhd68eee02009-12-11 03:44:18 +00001512** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
1513** is returned immediately upon encountering the lock. ^If the busy callback
1514** is not NULL, then the callback might be invoked with two arguments.
mihailimdb4f2ad2008-06-21 11:20:48 +00001515**
drhd68eee02009-12-11 03:44:18 +00001516** ^The first argument to the busy handler is a copy of the void* pointer which
1517** is the third argument to sqlite3_busy_handler(). ^The second argument to
1518** the busy handler callback is the number of times that the busy handler has
1519** been invoked for this locking event. ^If the
drh6ed48bf2007-06-14 20:57:18 +00001520** busy callback returns 0, then no additional attempts are made to
1521** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
drhd68eee02009-12-11 03:44:18 +00001522** ^If the callback returns non-zero, then another attempt
drhfddfa2d2007-12-05 18:05:16 +00001523** is made to open the database for reading and the cycle repeats.
drh2dfbbca2000-07-28 14:32:48 +00001524**
mihailimdb4f2ad2008-06-21 11:20:48 +00001525** The presence of a busy handler does not guarantee that it will be invoked
drhd68eee02009-12-11 03:44:18 +00001526** when there is lock contention. ^If SQLite determines that invoking the busy
mihailimdb4f2ad2008-06-21 11:20:48 +00001527** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
1528** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
drh86939b52007-01-10 12:54:51 +00001529** Consider a scenario where one process is holding a read lock that
1530** it is trying to promote to a reserved lock and
1531** a second process is holding a reserved lock that it is trying
1532** to promote to an exclusive lock. The first process cannot proceed
1533** because it is blocked by the second and the second process cannot
1534** proceed because it is blocked by the first. If both processes
drhf5befa02007-12-06 02:42:07 +00001535** invoke the busy handlers, neither will make any progress. Therefore,
drh6ed48bf2007-06-14 20:57:18 +00001536** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
drh86939b52007-01-10 12:54:51 +00001537** will induce the first process to release its read lock and allow
1538** the second process to proceed.
1539**
drhd68eee02009-12-11 03:44:18 +00001540** ^The default busy callback is NULL.
drh2dfbbca2000-07-28 14:32:48 +00001541**
drhd68eee02009-12-11 03:44:18 +00001542** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
drhfddfa2d2007-12-05 18:05:16 +00001543** when SQLite is in the middle of a large transaction where all the
drh33c1be32008-01-30 16:16:14 +00001544** changes will not fit into the in-memory cache. SQLite will
drh6ed48bf2007-06-14 20:57:18 +00001545** already hold a RESERVED lock on the database file, but it needs
1546** to promote this lock to EXCLUSIVE so that it can spill cache
1547** pages into the database file without harm to concurrent
drhd68eee02009-12-11 03:44:18 +00001548** readers. ^If it is unable to promote the lock, then the in-memory
drh6ed48bf2007-06-14 20:57:18 +00001549** cache will be left in an inconsistent state and so the error
1550** code is promoted from the relatively benign [SQLITE_BUSY] to
drhd68eee02009-12-11 03:44:18 +00001551** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
drh33c1be32008-01-30 16:16:14 +00001552** forces an automatic rollback of the changes. See the
mihailimdb4f2ad2008-06-21 11:20:48 +00001553** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
drh6ed48bf2007-06-14 20:57:18 +00001554** CorruptionFollowingBusyError</a> wiki page for a discussion of why
1555** this is important.
mihailimdb4f2ad2008-06-21 11:20:48 +00001556**
drhd68eee02009-12-11 03:44:18 +00001557** ^(There can only be a single busy handler defined for each
mihailimdb4f2ad2008-06-21 11:20:48 +00001558** [database connection]. Setting a new busy handler clears any
drhd68eee02009-12-11 03:44:18 +00001559** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
mihailimdb4f2ad2008-06-21 11:20:48 +00001560** will also set or clear the busy handler.
drhd677b3d2007-08-20 22:48:41 +00001561**
drhc8075422008-09-10 13:09:23 +00001562** The busy callback should not take any actions which modify the
1563** database connection that invoked the busy handler. Any such actions
1564** result in undefined behavior.
1565**
drh8b39db12009-02-18 18:37:58 +00001566** A busy handler must not close the database connection
1567** or [prepared statement] that invoked the busy handler.
drh2dfbbca2000-07-28 14:32:48 +00001568*/
danielk1977f9d64d22004-06-19 08:18:07 +00001569int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
drh2dfbbca2000-07-28 14:32:48 +00001570
1571/*
drhd68eee02009-12-11 03:44:18 +00001572** CAPI3REF: Set A Busy Timeout
drh6ed48bf2007-06-14 20:57:18 +00001573**
drhd68eee02009-12-11 03:44:18 +00001574** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
1575** for a specified amount of time when a table is locked. ^The handler
mihailimdb4f2ad2008-06-21 11:20:48 +00001576** will sleep multiple times until at least "ms" milliseconds of sleeping
drhd68eee02009-12-11 03:44:18 +00001577** have accumulated. ^After at least "ms" milliseconds of sleeping,
mihailimdb4f2ad2008-06-21 11:20:48 +00001578** the handler returns 0 which causes [sqlite3_step()] to return
1579** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
drh2dfbbca2000-07-28 14:32:48 +00001580**
drhd68eee02009-12-11 03:44:18 +00001581** ^Calling this routine with an argument less than or equal to zero
drh2dfbbca2000-07-28 14:32:48 +00001582** turns off all busy handlers.
drh6ed48bf2007-06-14 20:57:18 +00001583**
drhd68eee02009-12-11 03:44:18 +00001584** ^(There can only be a single busy handler for a particular
mihailimdb4f2ad2008-06-21 11:20:48 +00001585** [database connection] any any given moment. If another busy handler
1586** was defined (using [sqlite3_busy_handler()]) prior to calling
drhd68eee02009-12-11 03:44:18 +00001587** this routine, that other busy handler is cleared.)^
drh2dfbbca2000-07-28 14:32:48 +00001588*/
danielk1977f9d64d22004-06-19 08:18:07 +00001589int sqlite3_busy_timeout(sqlite3*, int ms);
drh2dfbbca2000-07-28 14:32:48 +00001590
drhe3710332000-09-29 13:30:53 +00001591/*
drhd68eee02009-12-11 03:44:18 +00001592** CAPI3REF: Convenience Routines For Running Queries
drh6ed48bf2007-06-14 20:57:18 +00001593**
drh33c1be32008-01-30 16:16:14 +00001594** Definition: A <b>result table</b> is memory data structure created by the
1595** [sqlite3_get_table()] interface. A result table records the
1596** complete query results from one or more queries.
drha18c5682000-10-08 22:20:57 +00001597**
drh33c1be32008-01-30 16:16:14 +00001598** The table conceptually has a number of rows and columns. But
1599** these numbers are not part of the result table itself. These
1600** numbers are obtained separately. Let N be the number of rows
1601** and M be the number of columns.
1602**
mihailimdb4f2ad2008-06-21 11:20:48 +00001603** A result table is an array of pointers to zero-terminated UTF-8 strings.
1604** There are (N+1)*M elements in the array. The first M pointers point
1605** to zero-terminated strings that contain the names of the columns.
1606** The remaining entries all point to query results. NULL values result
1607** in NULL pointers. All other values are in their UTF-8 zero-terminated
1608** string representation as returned by [sqlite3_column_text()].
drh33c1be32008-01-30 16:16:14 +00001609**
mihailimdb4f2ad2008-06-21 11:20:48 +00001610** A result table might consist of one or more memory allocations.
drh33c1be32008-01-30 16:16:14 +00001611** It is not safe to pass a result table directly to [sqlite3_free()].
1612** A result table should be deallocated using [sqlite3_free_table()].
1613**
1614** As an example of the result table format, suppose a query result
1615** is as follows:
drha18c5682000-10-08 22:20:57 +00001616**
drh8bacf972007-08-25 16:21:29 +00001617** <blockquote><pre>
drha18c5682000-10-08 22:20:57 +00001618** Name | Age
1619** -----------------------
1620** Alice | 43
1621** Bob | 28
1622** Cindy | 21
drh8bacf972007-08-25 16:21:29 +00001623** </pre></blockquote>
drha18c5682000-10-08 22:20:57 +00001624**
drh33c1be32008-01-30 16:16:14 +00001625** There are two column (M==2) and three rows (N==3). Thus the
1626** result table has 8 entries. Suppose the result table is stored
1627** in an array names azResult. Then azResult holds this content:
drha18c5682000-10-08 22:20:57 +00001628**
drh8bacf972007-08-25 16:21:29 +00001629** <blockquote><pre>
1630** azResult&#91;0] = "Name";
1631** azResult&#91;1] = "Age";
1632** azResult&#91;2] = "Alice";
1633** azResult&#91;3] = "43";
1634** azResult&#91;4] = "Bob";
1635** azResult&#91;5] = "28";
1636** azResult&#91;6] = "Cindy";
1637** azResult&#91;7] = "21";
1638** </pre></blockquote>
drha18c5682000-10-08 22:20:57 +00001639**
drhd68eee02009-12-11 03:44:18 +00001640** ^The sqlite3_get_table() function evaluates one or more
drh33c1be32008-01-30 16:16:14 +00001641** semicolon-separated SQL statements in the zero-terminated UTF-8
drhd68eee02009-12-11 03:44:18 +00001642** string of its 2nd parameter and returns a result table to the
drh33c1be32008-01-30 16:16:14 +00001643** pointer given in its 3rd parameter.
drha18c5682000-10-08 22:20:57 +00001644**
drhd68eee02009-12-11 03:44:18 +00001645** After the application has finished with the result from sqlite3_get_table(),
1646** it should pass the result table pointer to sqlite3_free_table() in order to
mihailimdb4f2ad2008-06-21 11:20:48 +00001647** release the memory that was malloced. Because of the way the
drh33c1be32008-01-30 16:16:14 +00001648** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
mihailimdb4f2ad2008-06-21 11:20:48 +00001649** function must not try to call [sqlite3_free()] directly. Only
drh33c1be32008-01-30 16:16:14 +00001650** [sqlite3_free_table()] is able to release the memory properly and safely.
drhe3710332000-09-29 13:30:53 +00001651**
drhd68eee02009-12-11 03:44:18 +00001652** ^(The sqlite3_get_table() interface is implemented as a wrapper around
drh33c1be32008-01-30 16:16:14 +00001653** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
1654** to any internal data structures of SQLite. It uses only the public
1655** interface defined here. As a consequence, errors that occur in the
1656** wrapper layer outside of the internal [sqlite3_exec()] call are not
drhd68eee02009-12-11 03:44:18 +00001657** reflected in subsequent calls to [sqlite3_errcode()] or
1658** [sqlite3_errmsg()].)^
drhe3710332000-09-29 13:30:53 +00001659*/
danielk19776f8a5032004-05-10 10:34:51 +00001660int sqlite3_get_table(
drhcf538f42008-06-27 14:51:52 +00001661 sqlite3 *db, /* An open database */
1662 const char *zSql, /* SQL to be evaluated */
1663 char ***pazResult, /* Results of the query */
1664 int *pnRow, /* Number of result rows written here */
1665 int *pnColumn, /* Number of result columns written here */
1666 char **pzErrmsg /* Error msg written here */
drhe3710332000-09-29 13:30:53 +00001667);
danielk19776f8a5032004-05-10 10:34:51 +00001668void sqlite3_free_table(char **result);
drhe3710332000-09-29 13:30:53 +00001669
drha18c5682000-10-08 22:20:57 +00001670/*
drhd68eee02009-12-11 03:44:18 +00001671** CAPI3REF: Formatted String Printing Functions
drh6ed48bf2007-06-14 20:57:18 +00001672**
shane7c7c3112009-08-17 15:31:23 +00001673** These routines are work-alikes of the "printf()" family of functions
drh6ed48bf2007-06-14 20:57:18 +00001674** from the standard C library.
1675**
drhd68eee02009-12-11 03:44:18 +00001676** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
drh6d2069d2007-08-14 01:58:53 +00001677** results into memory obtained from [sqlite3_malloc()].
drh33c1be32008-01-30 16:16:14 +00001678** The strings returned by these two routines should be
drhd68eee02009-12-11 03:44:18 +00001679** released by [sqlite3_free()]. ^Both routines return a
drh6ed48bf2007-06-14 20:57:18 +00001680** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
1681** memory to hold the resulting string.
1682**
drhd68eee02009-12-11 03:44:18 +00001683** ^(In sqlite3_snprintf() routine is similar to "snprintf()" from
drh6ed48bf2007-06-14 20:57:18 +00001684** the standard C library. The result is written into the
1685** buffer supplied as the second parameter whose size is given by
drh33c1be32008-01-30 16:16:14 +00001686** the first parameter. Note that the order of the
drhd68eee02009-12-11 03:44:18 +00001687** first two parameters is reversed from snprintf().)^ This is an
drh6ed48bf2007-06-14 20:57:18 +00001688** historical accident that cannot be fixed without breaking
drhd68eee02009-12-11 03:44:18 +00001689** backwards compatibility. ^(Note also that sqlite3_snprintf()
drh6ed48bf2007-06-14 20:57:18 +00001690** returns a pointer to its buffer instead of the number of
drhd68eee02009-12-11 03:44:18 +00001691** characters actually written into the buffer.)^ We admit that
drh6ed48bf2007-06-14 20:57:18 +00001692** the number of characters written would be a more useful return
1693** value but we cannot change the implementation of sqlite3_snprintf()
1694** now without breaking compatibility.
1695**
drhd68eee02009-12-11 03:44:18 +00001696** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
1697** guarantees that the buffer is always zero-terminated. ^The first
drh6ed48bf2007-06-14 20:57:18 +00001698** parameter "n" is the total size of the buffer, including space for
drh33c1be32008-01-30 16:16:14 +00001699** the zero terminator. So the longest string that can be completely
drh6ed48bf2007-06-14 20:57:18 +00001700** written will be n-1 characters.
1701**
1702** These routines all implement some additional formatting
drh4f26d6c2004-05-26 23:25:30 +00001703** options that are useful for constructing SQL statements.
shane26b34032008-05-23 17:21:09 +00001704** All of the usual printf() formatting options apply. In addition, there
drh153c62c2007-08-24 03:51:33 +00001705** is are "%q", "%Q", and "%z" options.
drh6ed48bf2007-06-14 20:57:18 +00001706**
drhd68eee02009-12-11 03:44:18 +00001707** ^(The %q option works like %s in that it substitutes a null-terminated
drh66b89c82000-11-28 20:47:17 +00001708** string from the argument list. But %q also doubles every '\'' character.
drhd68eee02009-12-11 03:44:18 +00001709** %q is designed for use inside a string literal.)^ By doubling each '\''
drh66b89c82000-11-28 20:47:17 +00001710** character it escapes that character and allows it to be inserted into
drha18c5682000-10-08 22:20:57 +00001711** the string.
1712**
mihailimdb4f2ad2008-06-21 11:20:48 +00001713** For example, assume the string variable zText contains text as follows:
drha18c5682000-10-08 22:20:57 +00001714**
drh6ed48bf2007-06-14 20:57:18 +00001715** <blockquote><pre>
1716** char *zText = "It's a happy day!";
1717** </pre></blockquote>
drha18c5682000-10-08 22:20:57 +00001718**
drh6ed48bf2007-06-14 20:57:18 +00001719** One can use this text in an SQL statement as follows:
drha18c5682000-10-08 22:20:57 +00001720**
drh6ed48bf2007-06-14 20:57:18 +00001721** <blockquote><pre>
1722** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
1723** sqlite3_exec(db, zSQL, 0, 0, 0);
1724** sqlite3_free(zSQL);
1725** </pre></blockquote>
drha18c5682000-10-08 22:20:57 +00001726**
1727** Because the %q format string is used, the '\'' character in zText
1728** is escaped and the SQL generated is as follows:
1729**
drh6ed48bf2007-06-14 20:57:18 +00001730** <blockquote><pre>
1731** INSERT INTO table1 VALUES('It''s a happy day!')
1732** </pre></blockquote>
drha18c5682000-10-08 22:20:57 +00001733**
1734** This is correct. Had we used %s instead of %q, the generated SQL
1735** would have looked like this:
1736**
drh6ed48bf2007-06-14 20:57:18 +00001737** <blockquote><pre>
1738** INSERT INTO table1 VALUES('It's a happy day!');
1739** </pre></blockquote>
drha18c5682000-10-08 22:20:57 +00001740**
mihailimdb4f2ad2008-06-21 11:20:48 +00001741** This second example is an SQL syntax error. As a general rule you should
1742** always use %q instead of %s when inserting text into a string literal.
drh6ed48bf2007-06-14 20:57:18 +00001743**
drhd68eee02009-12-11 03:44:18 +00001744** ^(The %Q option works like %q except it also adds single quotes around
mihailimdb4f2ad2008-06-21 11:20:48 +00001745** the outside of the total string. Additionally, if the parameter in the
1746** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
drhd68eee02009-12-11 03:44:18 +00001747** single quotes).)^ So, for example, one could say:
drh6ed48bf2007-06-14 20:57:18 +00001748**
1749** <blockquote><pre>
1750** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
1751** sqlite3_exec(db, zSQL, 0, 0, 0);
1752** sqlite3_free(zSQL);
1753** </pre></blockquote>
1754**
1755** The code above will render a correct SQL statement in the zSQL
1756** variable even if the zText variable is a NULL pointer.
drh153c62c2007-08-24 03:51:33 +00001757**
drhd68eee02009-12-11 03:44:18 +00001758** ^(The "%z" formatting option works like "%s" but with the
drh153c62c2007-08-24 03:51:33 +00001759** addition that after the string has been read and copied into
drhd68eee02009-12-11 03:44:18 +00001760** the result, [sqlite3_free()] is called on the input string.)^
drha18c5682000-10-08 22:20:57 +00001761*/
danielk19776f8a5032004-05-10 10:34:51 +00001762char *sqlite3_mprintf(const char*,...);
1763char *sqlite3_vmprintf(const char*, va_list);
drhfeac5f82004-08-01 00:10:45 +00001764char *sqlite3_snprintf(int,char*,const char*, ...);
drh5191b7e2002-03-08 02:12:00 +00001765
drh28dd4792006-06-26 21:35:44 +00001766/*
drhd68eee02009-12-11 03:44:18 +00001767** CAPI3REF: Memory Allocation Subsystem
drhd84f9462007-08-15 11:28:56 +00001768**
drhd68eee02009-12-11 03:44:18 +00001769** The SQLite core uses these three routines for all of its own
drh33c1be32008-01-30 16:16:14 +00001770** internal memory allocation needs. "Core" in the previous sentence
drhf5befa02007-12-06 02:42:07 +00001771** does not include operating-system specific VFS implementation. The
shane26b34032008-05-23 17:21:09 +00001772** Windows VFS uses native malloc() and free() for some operations.
drhd64621d2007-11-05 17:54:17 +00001773**
drhd68eee02009-12-11 03:44:18 +00001774** ^The sqlite3_malloc() routine returns a pointer to a block
drhfddfa2d2007-12-05 18:05:16 +00001775** of memory at least N bytes in length, where N is the parameter.
drhd68eee02009-12-11 03:44:18 +00001776** ^If sqlite3_malloc() is unable to obtain sufficient free
1777** memory, it returns a NULL pointer. ^If the parameter N to
drhfddfa2d2007-12-05 18:05:16 +00001778** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
1779** a NULL pointer.
1780**
drhd68eee02009-12-11 03:44:18 +00001781** ^Calling sqlite3_free() with a pointer previously returned
drhfddfa2d2007-12-05 18:05:16 +00001782** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
drhd68eee02009-12-11 03:44:18 +00001783** that it might be reused. ^The sqlite3_free() routine is
drhfddfa2d2007-12-05 18:05:16 +00001784** a no-op if is called with a NULL pointer. Passing a NULL pointer
drh33c1be32008-01-30 16:16:14 +00001785** to sqlite3_free() is harmless. After being freed, memory
drhfddfa2d2007-12-05 18:05:16 +00001786** should neither be read nor written. Even reading previously freed
1787** memory might result in a segmentation fault or other severe error.
drh33c1be32008-01-30 16:16:14 +00001788** Memory corruption, a segmentation fault, or other severe error
drhfddfa2d2007-12-05 18:05:16 +00001789** might result if sqlite3_free() is called with a non-NULL pointer that
drh7b228b32008-10-17 15:10:37 +00001790** was not obtained from sqlite3_malloc() or sqlite3_realloc().
drhfddfa2d2007-12-05 18:05:16 +00001791**
drhd68eee02009-12-11 03:44:18 +00001792** ^(The sqlite3_realloc() interface attempts to resize a
drhfddfa2d2007-12-05 18:05:16 +00001793** prior memory allocation to be at least N bytes, where N is the
1794** second parameter. The memory allocation to be resized is the first
drhd68eee02009-12-11 03:44:18 +00001795** parameter.)^ ^ If the first parameter to sqlite3_realloc()
drhfddfa2d2007-12-05 18:05:16 +00001796** is a NULL pointer then its behavior is identical to calling
1797** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
drhd68eee02009-12-11 03:44:18 +00001798** ^If the second parameter to sqlite3_realloc() is zero or
drhfddfa2d2007-12-05 18:05:16 +00001799** negative then the behavior is exactly the same as calling
1800** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
drhd68eee02009-12-11 03:44:18 +00001801** ^sqlite3_realloc() returns a pointer to a memory allocation
drhfddfa2d2007-12-05 18:05:16 +00001802** of at least N bytes in size or NULL if sufficient memory is unavailable.
drhd68eee02009-12-11 03:44:18 +00001803** ^If M is the size of the prior allocation, then min(N,M) bytes
drhfddfa2d2007-12-05 18:05:16 +00001804** of the prior allocation are copied into the beginning of buffer returned
1805** by sqlite3_realloc() and the prior allocation is freed.
drhd68eee02009-12-11 03:44:18 +00001806** ^If sqlite3_realloc() returns NULL, then the prior allocation
drhfddfa2d2007-12-05 18:05:16 +00001807** is not freed.
1808**
drhd68eee02009-12-11 03:44:18 +00001809** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
1810** is always aligned to at least an 8 byte boundary.
drhd64621d2007-11-05 17:54:17 +00001811**
1812** In SQLite version 3.5.0 and 3.5.1, it was possible to define
1813** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
1814** implementation of these routines to be omitted. That capability
mihailimdb4f2ad2008-06-21 11:20:48 +00001815** is no longer provided. Only built-in memory allocators can be used.
drh8bacf972007-08-25 16:21:29 +00001816**
shane26b34032008-05-23 17:21:09 +00001817** The Windows OS interface layer calls
drh8bacf972007-08-25 16:21:29 +00001818** the system malloc() and free() directly when converting
1819** filenames between the UTF-8 encoding used by SQLite
shane26b34032008-05-23 17:21:09 +00001820** and whatever filename encoding is used by the particular Windows
drh8bacf972007-08-25 16:21:29 +00001821** installation. Memory allocation errors are detected, but
1822** they are reported back as [SQLITE_CANTOPEN] or
1823** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
drh33c1be32008-01-30 16:16:14 +00001824**
drh8b39db12009-02-18 18:37:58 +00001825** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
1826** must be either NULL or else pointers obtained from a prior
1827** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
1828** not yet been released.
drh33c1be32008-01-30 16:16:14 +00001829**
drh8b39db12009-02-18 18:37:58 +00001830** The application must not read or write any part of
1831** a block of memory after it has been released using
1832** [sqlite3_free()] or [sqlite3_realloc()].
drh28dd4792006-06-26 21:35:44 +00001833*/
drhf3a65f72007-08-22 20:18:21 +00001834void *sqlite3_malloc(int);
1835void *sqlite3_realloc(void*, int);
drh28dd4792006-06-26 21:35:44 +00001836void sqlite3_free(void*);
1837
drh5191b7e2002-03-08 02:12:00 +00001838/*
drhd68eee02009-12-11 03:44:18 +00001839** CAPI3REF: Memory Allocator Statistics
drhd84f9462007-08-15 11:28:56 +00001840**
drh33c1be32008-01-30 16:16:14 +00001841** SQLite provides these two interfaces for reporting on the status
1842** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
mihailimdb4f2ad2008-06-21 11:20:48 +00001843** routines, which form the built-in memory allocation subsystem.
drhd84f9462007-08-15 11:28:56 +00001844**
drhd68eee02009-12-11 03:44:18 +00001845** ^The [sqlite3_memory_used()] routine returns the number of bytes
1846** of memory currently outstanding (malloced but not freed).
1847** ^The [sqlite3_memory_highwater()] routine returns the maximum
1848** value of [sqlite3_memory_used()] since the high-water mark
1849** was last reset. ^The values returned by [sqlite3_memory_used()] and
1850** [sqlite3_memory_highwater()] include any overhead
1851** added by SQLite in its implementation of [sqlite3_malloc()],
1852** but not overhead added by the any underlying system library
1853** routines that [sqlite3_malloc()] may call.
1854**
1855** ^The memory high-water mark is reset to the current value of
1856** [sqlite3_memory_used()] if and only if the parameter to
1857** [sqlite3_memory_highwater()] is true. ^The value returned
1858** by [sqlite3_memory_highwater(1)] is the high-water mark
1859** prior to the reset.
drhd84f9462007-08-15 11:28:56 +00001860*/
drh153c62c2007-08-24 03:51:33 +00001861sqlite3_int64 sqlite3_memory_used(void);
1862sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
drhd84f9462007-08-15 11:28:56 +00001863
1864/*
drhd68eee02009-12-11 03:44:18 +00001865** CAPI3REF: Pseudo-Random Number Generator
drh2fa18682008-03-19 14:15:34 +00001866**
1867** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
drh49c3d572008-12-15 22:51:38 +00001868** select random [ROWID | ROWIDs] when inserting new records into a table that
1869** already uses the largest possible [ROWID]. The PRNG is also used for
drh2fa18682008-03-19 14:15:34 +00001870** the build-in random() and randomblob() SQL functions. This interface allows
shane26b34032008-05-23 17:21:09 +00001871** applications to access the same PRNG for other purposes.
drh2fa18682008-03-19 14:15:34 +00001872**
drhd68eee02009-12-11 03:44:18 +00001873** ^A call to this routine stores N bytes of randomness into buffer P.
drh2fa18682008-03-19 14:15:34 +00001874**
drhd68eee02009-12-11 03:44:18 +00001875** ^The first time this routine is invoked (either internally or by
drh2fa18682008-03-19 14:15:34 +00001876** the application) the PRNG is seeded using randomness obtained
1877** from the xRandomness method of the default [sqlite3_vfs] object.
drhd68eee02009-12-11 03:44:18 +00001878** ^On all subsequent invocations, the pseudo-randomness is generated
drh2fa18682008-03-19 14:15:34 +00001879** internally and without recourse to the [sqlite3_vfs] xRandomness
1880** method.
drh2fa18682008-03-19 14:15:34 +00001881*/
1882void sqlite3_randomness(int N, void *P);
1883
1884/*
drhd68eee02009-12-11 03:44:18 +00001885** CAPI3REF: Compile-Time Authorization Callbacks
drhfddfa2d2007-12-05 18:05:16 +00001886**
drhd68eee02009-12-11 03:44:18 +00001887** ^This routine registers a authorizer callback with a particular
drhf47ce562008-03-20 18:00:49 +00001888** [database connection], supplied in the first argument.
drhd68eee02009-12-11 03:44:18 +00001889** ^The authorizer callback is invoked as SQL statements are being compiled
drh6ed48bf2007-06-14 20:57:18 +00001890** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
drhd68eee02009-12-11 03:44:18 +00001891** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
drh6ed48bf2007-06-14 20:57:18 +00001892** points during the compilation process, as logic is being created
1893** to perform various actions, the authorizer callback is invoked to
drhd68eee02009-12-11 03:44:18 +00001894** see if those actions are allowed. ^The authorizer callback should
drhf47ce562008-03-20 18:00:49 +00001895** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
drh6ed48bf2007-06-14 20:57:18 +00001896** specific action but allow the SQL statement to continue to be
1897** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
drhd68eee02009-12-11 03:44:18 +00001898** rejected with an error. ^If the authorizer callback returns
drhf5befa02007-12-06 02:42:07 +00001899** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
mihailima3f64902008-06-21 13:35:56 +00001900** then the [sqlite3_prepare_v2()] or equivalent call that triggered
drh33c1be32008-01-30 16:16:14 +00001901** the authorizer will fail with an error message.
drh6ed48bf2007-06-14 20:57:18 +00001902**
drhf5befa02007-12-06 02:42:07 +00001903** When the callback returns [SQLITE_OK], that means the operation
drhd68eee02009-12-11 03:44:18 +00001904** requested is ok. ^When the callback returns [SQLITE_DENY], the
drhf5befa02007-12-06 02:42:07 +00001905** [sqlite3_prepare_v2()] or equivalent call that triggered the
drh33c1be32008-01-30 16:16:14 +00001906** authorizer will fail with an error message explaining that
drh959b5302009-04-30 15:59:56 +00001907** access is denied.
drh6ed48bf2007-06-14 20:57:18 +00001908**
drhd68eee02009-12-11 03:44:18 +00001909** ^The first parameter to the authorizer callback is a copy of the third
1910** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
mihailima3f64902008-06-21 13:35:56 +00001911** to the callback is an integer [SQLITE_COPY | action code] that specifies
drhd68eee02009-12-11 03:44:18 +00001912** the particular action to be authorized. ^The third through sixth parameters
mihailima3f64902008-06-21 13:35:56 +00001913** to the callback are zero-terminated strings that contain additional
1914** details about the action to be authorized.
drh6ed48bf2007-06-14 20:57:18 +00001915**
drhd68eee02009-12-11 03:44:18 +00001916** ^If the action code is [SQLITE_READ]
drh959b5302009-04-30 15:59:56 +00001917** and the callback returns [SQLITE_IGNORE] then the
1918** [prepared statement] statement is constructed to substitute
1919** a NULL value in place of the table column that would have
1920** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
1921** return can be used to deny an untrusted user access to individual
1922** columns of a table.
drhd68eee02009-12-11 03:44:18 +00001923** ^If the action code is [SQLITE_DELETE] and the callback returns
drh959b5302009-04-30 15:59:56 +00001924** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
1925** [truncate optimization] is disabled and all rows are deleted individually.
1926**
drhf47ce562008-03-20 18:00:49 +00001927** An authorizer is used when [sqlite3_prepare | preparing]
mihailimebe796c2008-06-21 20:11:17 +00001928** SQL statements from an untrusted source, to ensure that the SQL statements
1929** do not try to access data they are not allowed to see, or that they do not
1930** try to execute malicious statements that damage the database. For
drh6ed48bf2007-06-14 20:57:18 +00001931** example, an application may allow a user to enter arbitrary
1932** SQL queries for evaluation by a database. But the application does
1933** not want the user to be able to make arbitrary changes to the
1934** database. An authorizer could then be put in place while the
drhf47ce562008-03-20 18:00:49 +00001935** user-entered SQL is being [sqlite3_prepare | prepared] that
1936** disallows everything except [SELECT] statements.
1937**
1938** Applications that need to process SQL from untrusted sources
1939** might also consider lowering resource limits using [sqlite3_limit()]
1940** and limiting database size using the [max_page_count] [PRAGMA]
1941** in addition to using an authorizer.
drh6ed48bf2007-06-14 20:57:18 +00001942**
drhd68eee02009-12-11 03:44:18 +00001943** ^(Only a single authorizer can be in place on a database connection
drh6ed48bf2007-06-14 20:57:18 +00001944** at a time. Each call to sqlite3_set_authorizer overrides the
drhd68eee02009-12-11 03:44:18 +00001945** previous call.)^ ^Disable the authorizer by installing a NULL callback.
drh33c1be32008-01-30 16:16:14 +00001946** The authorizer is disabled by default.
drh6ed48bf2007-06-14 20:57:18 +00001947**
drhc8075422008-09-10 13:09:23 +00001948** The authorizer callback must not do anything that will modify
1949** the database connection that invoked the authorizer callback.
1950** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
1951** database connections for the meaning of "modify" in this paragraph.
1952**
drhd68eee02009-12-11 03:44:18 +00001953** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
shane7c7c3112009-08-17 15:31:23 +00001954** statement might be re-prepared during [sqlite3_step()] due to a
drh7b37c5d2008-08-12 14:51:29 +00001955** schema change. Hence, the application should ensure that the
1956** correct authorizer callback remains in place during the [sqlite3_step()].
1957**
drhd68eee02009-12-11 03:44:18 +00001958** ^Note that the authorizer callback is invoked only during
drh33c1be32008-01-30 16:16:14 +00001959** [sqlite3_prepare()] or its variants. Authorization is not
drh959b5302009-04-30 15:59:56 +00001960** performed during statement evaluation in [sqlite3_step()], unless
1961** as stated in the previous paragraph, sqlite3_step() invokes
1962** sqlite3_prepare_v2() to reprepare a statement after a schema change.
drhed6c8672003-01-12 18:02:16 +00001963*/
danielk19776f8a5032004-05-10 10:34:51 +00001964int sqlite3_set_authorizer(
danielk1977f9d64d22004-06-19 08:18:07 +00001965 sqlite3*,
drhe22a3342003-04-22 20:30:37 +00001966 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
drhe5f9c642003-01-13 23:27:31 +00001967 void *pUserData
drhed6c8672003-01-12 18:02:16 +00001968);
1969
1970/*
drhd68eee02009-12-11 03:44:18 +00001971** CAPI3REF: Authorizer Return Codes
drh6ed48bf2007-06-14 20:57:18 +00001972**
1973** The [sqlite3_set_authorizer | authorizer callback function] must
1974** return either [SQLITE_OK] or one of these two constants in order
1975** to signal SQLite whether or not the action is permitted. See the
1976** [sqlite3_set_authorizer | authorizer documentation] for additional
1977** information.
1978*/
1979#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
1980#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
1981
1982/*
drhd68eee02009-12-11 03:44:18 +00001983** CAPI3REF: Authorizer Action Codes
drh6ed48bf2007-06-14 20:57:18 +00001984**
1985** The [sqlite3_set_authorizer()] interface registers a callback function
mihailima3f64902008-06-21 13:35:56 +00001986** that is invoked to authorize certain SQL statement actions. The
drh6ed48bf2007-06-14 20:57:18 +00001987** second parameter to the callback is an integer code that specifies
1988** what action is being authorized. These are the integer action codes that
drh33c1be32008-01-30 16:16:14 +00001989** the authorizer callback may be passed.
drh6ed48bf2007-06-14 20:57:18 +00001990**
mihailima3f64902008-06-21 13:35:56 +00001991** These action code values signify what kind of operation is to be
drh33c1be32008-01-30 16:16:14 +00001992** authorized. The 3rd and 4th parameters to the authorization
drhf5befa02007-12-06 02:42:07 +00001993** callback function will be parameters or NULL depending on which of these
drhd68eee02009-12-11 03:44:18 +00001994** codes is used as the second parameter. ^The 5th parameter to the
mihailima3f64902008-06-21 13:35:56 +00001995** authorizer callback is the name of the database ("main", "temp",
drhd68eee02009-12-11 03:44:18 +00001996** etc.) if applicable. ^The 6th parameter to the authorizer callback
drh5cf590c2003-04-24 01:45:04 +00001997** is the name of the inner-most trigger or view that is responsible for
mihailima3f64902008-06-21 13:35:56 +00001998** the access attempt or NULL if this access attempt is directly from
drh6ed48bf2007-06-14 20:57:18 +00001999** top-level SQL code.
drhed6c8672003-01-12 18:02:16 +00002000*/
drh6ed48bf2007-06-14 20:57:18 +00002001/******************************************* 3rd ************ 4th ***********/
drhe5f9c642003-01-13 23:27:31 +00002002#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2003#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2004#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2005#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
drh77ad4e42003-01-14 02:49:27 +00002006#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
drhe5f9c642003-01-13 23:27:31 +00002007#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
drh77ad4e42003-01-14 02:49:27 +00002008#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
drhe5f9c642003-01-13 23:27:31 +00002009#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2010#define SQLITE_DELETE 9 /* Table Name NULL */
drh77ad4e42003-01-14 02:49:27 +00002011#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
drhe5f9c642003-01-13 23:27:31 +00002012#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
drh77ad4e42003-01-14 02:49:27 +00002013#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
drhe5f9c642003-01-13 23:27:31 +00002014#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
drh77ad4e42003-01-14 02:49:27 +00002015#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
drhe5f9c642003-01-13 23:27:31 +00002016#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
drh77ad4e42003-01-14 02:49:27 +00002017#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
drhe5f9c642003-01-13 23:27:31 +00002018#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2019#define SQLITE_INSERT 18 /* Table Name NULL */
2020#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2021#define SQLITE_READ 20 /* Table Name Column Name */
2022#define SQLITE_SELECT 21 /* NULL NULL */
danielk1977ab9b7032008-12-30 06:24:58 +00002023#define SQLITE_TRANSACTION 22 /* Operation NULL */
drhe5f9c642003-01-13 23:27:31 +00002024#define SQLITE_UPDATE 23 /* Table Name Column Name */
drh81e293b2003-06-06 19:00:42 +00002025#define SQLITE_ATTACH 24 /* Filename NULL */
2026#define SQLITE_DETACH 25 /* Database Name NULL */
danielk19771c8c23c2004-11-12 15:53:37 +00002027#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
danielk19771d54df82004-11-23 15:41:16 +00002028#define SQLITE_REINDEX 27 /* Index Name NULL */
drhe6e04962005-07-23 02:17:03 +00002029#define SQLITE_ANALYZE 28 /* Table Name NULL */
danielk1977f1a381e2006-06-16 08:01:02 +00002030#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2031#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
drh2e904c52008-11-10 23:54:05 +00002032#define SQLITE_FUNCTION 31 /* NULL Function Name */
danielk1977ab9b7032008-12-30 06:24:58 +00002033#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
drh6ed48bf2007-06-14 20:57:18 +00002034#define SQLITE_COPY 0 /* No longer used */
drhed6c8672003-01-12 18:02:16 +00002035
2036/*
drhd68eee02009-12-11 03:44:18 +00002037** CAPI3REF: Tracing And Profiling Functions
drhd5a68d32008-08-04 13:44:57 +00002038** EXPERIMENTAL
drh6ed48bf2007-06-14 20:57:18 +00002039**
2040** These routines register callback functions that can be used for
2041** tracing and profiling the execution of SQL statements.
drhfddfa2d2007-12-05 18:05:16 +00002042**
drhd68eee02009-12-11 03:44:18 +00002043** ^The callback function registered by sqlite3_trace() is invoked at
drh33c1be32008-01-30 16:16:14 +00002044** various times when an SQL statement is being run by [sqlite3_step()].
drhd68eee02009-12-11 03:44:18 +00002045** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2046** SQL statement text as the statement first begins executing.
2047** ^(Additional sqlite3_trace() callbacks might occur
shane26b34032008-05-23 17:21:09 +00002048** as each triggered subprogram is entered. The callbacks for triggers
drhd68eee02009-12-11 03:44:18 +00002049** contain a UTF-8 SQL comment that identifies the trigger.)^
mihailima3f64902008-06-21 13:35:56 +00002050**
drhd68eee02009-12-11 03:44:18 +00002051** ^The callback function registered by sqlite3_profile() is invoked
2052** as each SQL statement finishes. ^The profile callback contains
drh33c1be32008-01-30 16:16:14 +00002053** the original statement text and an estimate of wall-clock time
2054** of how long that statement took to run.
drh18de4822003-01-16 16:28:53 +00002055*/
shanea79c3cc2008-08-11 17:27:01 +00002056SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2057SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
drh6d2069d2007-08-14 01:58:53 +00002058 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
drh18de4822003-01-16 16:28:53 +00002059
danielk1977348bb5d2003-10-18 09:37:26 +00002060/*
drhd68eee02009-12-11 03:44:18 +00002061** CAPI3REF: Query Progress Callbacks
drh6ed48bf2007-06-14 20:57:18 +00002062**
drhd68eee02009-12-11 03:44:18 +00002063** ^This routine configures a callback function - the
drhfddfa2d2007-12-05 18:05:16 +00002064** progress callback - that is invoked periodically during long
2065** running calls to [sqlite3_exec()], [sqlite3_step()] and
mihailima3f64902008-06-21 13:35:56 +00002066** [sqlite3_get_table()]. An example use for this
drh6ed48bf2007-06-14 20:57:18 +00002067** interface is to keep a GUI updated during a large query.
danielk1977348bb5d2003-10-18 09:37:26 +00002068**
drhd68eee02009-12-11 03:44:18 +00002069** ^If the progress callback returns non-zero, the operation is
drh33c1be32008-01-30 16:16:14 +00002070** interrupted. This feature can be used to implement a
drhc8075422008-09-10 13:09:23 +00002071** "Cancel" button on a GUI progress dialog box.
2072**
2073** The progress handler must not do anything that will modify
2074** the database connection that invoked the progress handler.
2075** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2076** database connections for the meaning of "modify" in this paragraph.
danielk1977348bb5d2003-10-18 09:37:26 +00002077**
danielk1977348bb5d2003-10-18 09:37:26 +00002078*/
danielk1977f9d64d22004-06-19 08:18:07 +00002079void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
danielk1977348bb5d2003-10-18 09:37:26 +00002080
drhaa940ea2004-01-15 02:44:03 +00002081/*
drhd68eee02009-12-11 03:44:18 +00002082** CAPI3REF: Opening A New Database Connection
drhaa940ea2004-01-15 02:44:03 +00002083**
drhd68eee02009-12-11 03:44:18 +00002084** ^These routines open an SQLite database file whose name is given by the
2085** filename argument. ^The filename argument is interpreted as UTF-8 for
mihailima3f64902008-06-21 13:35:56 +00002086** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
drhd68eee02009-12-11 03:44:18 +00002087** order for sqlite3_open16(). ^(A [database connection] handle is usually
mihailima3f64902008-06-21 13:35:56 +00002088** returned in *ppDb, even if an error occurs. The only exception is that
2089** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2090** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
drhd68eee02009-12-11 03:44:18 +00002091** object.)^ ^(If the database is opened (and/or created) successfully, then
2092** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
mihailima3f64902008-06-21 13:35:56 +00002093** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
drhd68eee02009-12-11 03:44:18 +00002094** an English language description of the error following a failure of any
2095** of the sqlite3_open() routines.
drh22fbcb82004-02-01 01:22:50 +00002096**
drhd68eee02009-12-11 03:44:18 +00002097** ^The default encoding for the database will be UTF-8 if
mihailima3f64902008-06-21 13:35:56 +00002098** sqlite3_open() or sqlite3_open_v2() is called and
2099** UTF-16 in the native byte order if sqlite3_open16() is used.
danielk197765904932004-05-26 06:18:37 +00002100**
drh33c1be32008-01-30 16:16:14 +00002101** Whether or not an error occurs when it is opened, resources
mihailima3f64902008-06-21 13:35:56 +00002102** associated with the [database connection] handle should be released by
2103** passing it to [sqlite3_close()] when it is no longer required.
drh6d2069d2007-08-14 01:58:53 +00002104**
mihailima3f64902008-06-21 13:35:56 +00002105** The sqlite3_open_v2() interface works like sqlite3_open()
shane26b34032008-05-23 17:21:09 +00002106** except that it accepts two additional parameters for additional control
drhd68eee02009-12-11 03:44:18 +00002107** over the new database connection. ^(The flags parameter to
2108** sqlite3_open_v2() can take one of
danielk19779a6284c2008-07-10 17:52:49 +00002109** the following three values, optionally combined with the
drhf1f12682009-09-09 14:17:52 +00002110** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
drhd68eee02009-12-11 03:44:18 +00002111** and/or [SQLITE_OPEN_PRIVATECACHE] flags:)^
drh6d2069d2007-08-14 01:58:53 +00002112**
mihailima3f64902008-06-21 13:35:56 +00002113** <dl>
drhd68eee02009-12-11 03:44:18 +00002114** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
mihailima3f64902008-06-21 13:35:56 +00002115** <dd>The database is opened in read-only mode. If the database does not
drhd68eee02009-12-11 03:44:18 +00002116** already exist, an error is returned.</dd>)^
drh6d2069d2007-08-14 01:58:53 +00002117**
drhd68eee02009-12-11 03:44:18 +00002118** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
mihailima3f64902008-06-21 13:35:56 +00002119** <dd>The database is opened for reading and writing if possible, or reading
2120** only if the file is write protected by the operating system. In either
drhd68eee02009-12-11 03:44:18 +00002121** case the database must already exist, otherwise an error is returned.</dd>)^
drh9da9d962007-08-28 15:47:44 +00002122**
drhd68eee02009-12-11 03:44:18 +00002123** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
mihailima3f64902008-06-21 13:35:56 +00002124** <dd>The database is opened for reading and writing, and is creates it if
2125** it does not already exist. This is the behavior that is always used for
drhd68eee02009-12-11 03:44:18 +00002126** sqlite3_open() and sqlite3_open16().</dd>)^
mihailima3f64902008-06-21 13:35:56 +00002127** </dl>
2128**
2129** If the 3rd parameter to sqlite3_open_v2() is not one of the
danielk19779a6284c2008-07-10 17:52:49 +00002130** combinations shown above or one of the combinations shown above combined
drhf1f12682009-09-09 14:17:52 +00002131** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX],
2132** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_SHAREDCACHE] flags,
drhafacce02008-09-02 21:35:03 +00002133** then the behavior is undefined.
danielk19779a6284c2008-07-10 17:52:49 +00002134**
drhd68eee02009-12-11 03:44:18 +00002135** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
drhafacce02008-09-02 21:35:03 +00002136** opens in the multi-thread [threading mode] as long as the single-thread
drhd68eee02009-12-11 03:44:18 +00002137** mode has not been set at compile-time or start-time. ^If the
drhafacce02008-09-02 21:35:03 +00002138** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2139** in the serialized [threading mode] unless single-thread was
2140** previously selected at compile-time or start-time.
drhd68eee02009-12-11 03:44:18 +00002141** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
drhf1f12682009-09-09 14:17:52 +00002142** eligible to use [shared cache mode], regardless of whether or not shared
drhd68eee02009-12-11 03:44:18 +00002143** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
drhf1f12682009-09-09 14:17:52 +00002144** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2145** participate in [shared cache mode] even if it is enabled.
drhd9b97cf2008-04-10 13:38:17 +00002146**
drhd68eee02009-12-11 03:44:18 +00002147** ^If the filename is ":memory:", then a private, temporary in-memory database
2148** is created for the connection. ^This in-memory database will vanish when
mihailima3f64902008-06-21 13:35:56 +00002149** the database connection is closed. Future versions of SQLite might
2150** make use of additional special filenames that begin with the ":" character.
2151** It is recommended that when a database filename actually does begin with
2152** a ":" character you should prefix the filename with a pathname such as
2153** "./" to avoid ambiguity.
drh6d2069d2007-08-14 01:58:53 +00002154**
drhd68eee02009-12-11 03:44:18 +00002155** ^If the filename is an empty string, then a private, temporary
2156** on-disk database will be created. ^This private database will be
drh3f3b6352007-09-03 20:32:45 +00002157** automatically deleted as soon as the database connection is closed.
2158**
drhd68eee02009-12-11 03:44:18 +00002159** ^The fourth parameter to sqlite3_open_v2() is the name of the
mihailima3f64902008-06-21 13:35:56 +00002160** [sqlite3_vfs] object that defines the operating system interface that
drhd68eee02009-12-11 03:44:18 +00002161** the new database connection should use. ^If the fourth parameter is
mihailima3f64902008-06-21 13:35:56 +00002162** a NULL pointer then the default [sqlite3_vfs] object is used.
drh6ed48bf2007-06-14 20:57:18 +00002163**
shane26b34032008-05-23 17:21:09 +00002164** <b>Note to Windows users:</b> The encoding used for the filename argument
mihailima3f64902008-06-21 13:35:56 +00002165** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
drh9da9d962007-08-28 15:47:44 +00002166** codepage is currently defined. Filenames containing international
2167** characters must be converted to UTF-8 prior to passing them into
mihailima3f64902008-06-21 13:35:56 +00002168** sqlite3_open() or sqlite3_open_v2().
danielk197765904932004-05-26 06:18:37 +00002169*/
2170int sqlite3_open(
2171 const char *filename, /* Database filename (UTF-8) */
danielk19774f057f92004-06-08 00:02:33 +00002172 sqlite3 **ppDb /* OUT: SQLite db handle */
danielk197765904932004-05-26 06:18:37 +00002173);
danielk197765904932004-05-26 06:18:37 +00002174int sqlite3_open16(
2175 const void *filename, /* Database filename (UTF-16) */
danielk19774f057f92004-06-08 00:02:33 +00002176 sqlite3 **ppDb /* OUT: SQLite db handle */
danielk197765904932004-05-26 06:18:37 +00002177);
drh6d2069d2007-08-14 01:58:53 +00002178int sqlite3_open_v2(
drh428e2822007-08-30 16:23:19 +00002179 const char *filename, /* Database filename (UTF-8) */
drh6d2069d2007-08-14 01:58:53 +00002180 sqlite3 **ppDb, /* OUT: SQLite db handle */
2181 int flags, /* Flags */
drhd84f9462007-08-15 11:28:56 +00002182 const char *zVfs /* Name of VFS module to use */
drh6d2069d2007-08-14 01:58:53 +00002183);
danielk1977295ba552004-05-19 10:34:51 +00002184
danielk197765904932004-05-26 06:18:37 +00002185/*
drhd68eee02009-12-11 03:44:18 +00002186** CAPI3REF: Error Codes And Messages
drh6ed48bf2007-06-14 20:57:18 +00002187**
drhd68eee02009-12-11 03:44:18 +00002188** ^The sqlite3_errcode() interface returns the numeric [result code] or
mihailimefc8e8a2008-06-21 16:47:09 +00002189** [extended result code] for the most recent failed sqlite3_* API call
2190** associated with a [database connection]. If a prior API call failed
2191** but the most recent API call succeeded, the return value from
drhd68eee02009-12-11 03:44:18 +00002192** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
drh99dfe5e2008-10-30 15:03:15 +00002193** interface is the same except that it always returns the
2194** [extended result code] even when extended result codes are
2195** disabled.
drh6ed48bf2007-06-14 20:57:18 +00002196**
drhd68eee02009-12-11 03:44:18 +00002197** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
mihailimebe796c2008-06-21 20:11:17 +00002198** text that describes the error, as either UTF-8 or UTF-16 respectively.
drhd68eee02009-12-11 03:44:18 +00002199** ^(Memory to hold the error message string is managed internally.
mihailimefc8e8a2008-06-21 16:47:09 +00002200** The application does not need to worry about freeing the result.
mlcreech27358862008-03-01 23:34:46 +00002201** However, the error string might be overwritten or deallocated by
drhd68eee02009-12-11 03:44:18 +00002202** subsequent calls to other SQLite interface functions.)^
danielk197765904932004-05-26 06:18:37 +00002203**
drh2838b472008-11-04 14:48:22 +00002204** When the serialized [threading mode] is in use, it might be the
2205** case that a second error occurs on a separate thread in between
2206** the time of the first error and the call to these interfaces.
2207** When that happens, the second error will be reported since these
2208** interfaces always report the most recent result. To avoid
2209** this, each thread can obtain exclusive use of the [database connection] D
2210** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2211** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2212** all calls to the interfaces listed here are completed.
2213**
drhd55d57e2008-07-07 17:53:07 +00002214** If an interface fails with SQLITE_MISUSE, that means the interface
2215** was invoked incorrectly by the application. In that case, the
2216** error code and message may or may not be set.
danielk197765904932004-05-26 06:18:37 +00002217*/
2218int sqlite3_errcode(sqlite3 *db);
drh99dfe5e2008-10-30 15:03:15 +00002219int sqlite3_extended_errcode(sqlite3 *db);
danielk197765904932004-05-26 06:18:37 +00002220const char *sqlite3_errmsg(sqlite3*);
danielk197765904932004-05-26 06:18:37 +00002221const void *sqlite3_errmsg16(sqlite3*);
2222
2223/*
drhd68eee02009-12-11 03:44:18 +00002224** CAPI3REF: SQL Statement Object
drh33c1be32008-01-30 16:16:14 +00002225** KEYWORDS: {prepared statement} {prepared statements}
drh6ed48bf2007-06-14 20:57:18 +00002226**
mihailimefc8e8a2008-06-21 16:47:09 +00002227** An instance of this object represents a single SQL statement.
2228** This object is variously known as a "prepared statement" or a
drh6ed48bf2007-06-14 20:57:18 +00002229** "compiled SQL statement" or simply as a "statement".
mihailimefc8e8a2008-06-21 16:47:09 +00002230**
drh6ed48bf2007-06-14 20:57:18 +00002231** The life of a statement object goes something like this:
2232**
2233** <ol>
2234** <li> Create the object using [sqlite3_prepare_v2()] or a related
2235** function.
mihailimefc8e8a2008-06-21 16:47:09 +00002236** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2237** interfaces.
drh6ed48bf2007-06-14 20:57:18 +00002238** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2239** <li> Reset the statement using [sqlite3_reset()] then go back
2240** to step 2. Do this zero or more times.
2241** <li> Destroy the object using [sqlite3_finalize()].
2242** </ol>
2243**
2244** Refer to documentation on individual methods above for additional
2245** information.
danielk197765904932004-05-26 06:18:37 +00002246*/
danielk1977fc57d7b2004-05-26 02:04:57 +00002247typedef struct sqlite3_stmt sqlite3_stmt;
2248
danielk1977e3209e42004-05-20 01:40:18 +00002249/*
drhd68eee02009-12-11 03:44:18 +00002250** CAPI3REF: Run-time Limits
drhcaa639f2008-03-20 00:32:20 +00002251**
drhd68eee02009-12-11 03:44:18 +00002252** ^(This interface allows the size of various constructs to be limited
drhcaa639f2008-03-20 00:32:20 +00002253** on a connection by connection basis. The first parameter is the
2254** [database connection] whose limit is to be set or queried. The
2255** second parameter is one of the [limit categories] that define a
2256** class of constructs to be size limited. The third parameter is the
drhd68eee02009-12-11 03:44:18 +00002257** new limit for that construct. The function returns the old limit.)^
drhcaa639f2008-03-20 00:32:20 +00002258**
drhd68eee02009-12-11 03:44:18 +00002259** ^If the new limit is a negative number, the limit is unchanged.
2260** ^(For the limit category of SQLITE_LIMIT_XYZ there is a
drhae1a8802009-02-11 15:04:40 +00002261** [limits | hard upper bound]
2262** set by a compile-time C preprocessor macro named
2263** [limits | SQLITE_MAX_XYZ].
drhd68eee02009-12-11 03:44:18 +00002264** (The "_LIMIT_" in the name is changed to "_MAX_".))^
2265** ^Attempts to increase a limit above its hard upper bound are
drhf47ce562008-03-20 18:00:49 +00002266** silently truncated to the hard upper limit.
drhcaa639f2008-03-20 00:32:20 +00002267**
drhd68eee02009-12-11 03:44:18 +00002268** Run-time limits are intended for use in applications that manage
drhbb4957f2008-03-20 14:03:29 +00002269** both their own internal database and also databases that are controlled
2270** by untrusted external sources. An example application might be a
drh46f33ef2009-02-11 15:23:35 +00002271** web browser that has its own databases for storing history and
shane26b34032008-05-23 17:21:09 +00002272** separate databases controlled by JavaScript applications downloaded
shane236ce972008-05-30 15:35:30 +00002273** off the Internet. The internal databases can be given the
drhbb4957f2008-03-20 14:03:29 +00002274** large, default limits. Databases managed by external sources can
2275** be given much smaller limits designed to prevent a denial of service
mihailimefc8e8a2008-06-21 16:47:09 +00002276** attack. Developers might also want to use the [sqlite3_set_authorizer()]
drhf47ce562008-03-20 18:00:49 +00002277** interface to further control untrusted SQL. The size of the database
2278** created by an untrusted script can be contained using the
2279** [max_page_count] [PRAGMA].
drhbb4957f2008-03-20 14:03:29 +00002280**
drha911abe2008-07-16 13:29:51 +00002281** New run-time limit categories may be added in future releases.
drhcaa639f2008-03-20 00:32:20 +00002282*/
2283int sqlite3_limit(sqlite3*, int id, int newVal);
2284
2285/*
drhd68eee02009-12-11 03:44:18 +00002286** CAPI3REF: Run-Time Limit Categories
drhe7ae4e22009-11-02 15:51:52 +00002287** KEYWORDS: {limit category} {*limit categories}
mihailimefc8e8a2008-06-21 16:47:09 +00002288**
drh46f33ef2009-02-11 15:23:35 +00002289** These constants define various performance limits
2290** that can be lowered at run-time using [sqlite3_limit()].
2291** The synopsis of the meanings of the various limits is shown below.
2292** Additional information is available at [limits | Limits in SQLite].
drhbb4957f2008-03-20 14:03:29 +00002293**
2294** <dl>
drhd68eee02009-12-11 03:44:18 +00002295** ^(<dt>SQLITE_LIMIT_LENGTH</dt>
2296** <dd>The maximum size of any string or BLOB or table row.<dd>)^
drhbb4957f2008-03-20 14:03:29 +00002297**
drhd68eee02009-12-11 03:44:18 +00002298** ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
2299** <dd>The maximum length of an SQL statement.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002300**
drhd68eee02009-12-11 03:44:18 +00002301** ^(<dt>SQLITE_LIMIT_COLUMN</dt>
drhbb4957f2008-03-20 14:03:29 +00002302** <dd>The maximum number of columns in a table definition or in the
drh46f33ef2009-02-11 15:23:35 +00002303** result set of a [SELECT] or the maximum number of columns in an index
drhd68eee02009-12-11 03:44:18 +00002304** or in an ORDER BY or GROUP BY clause.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002305**
drhd68eee02009-12-11 03:44:18 +00002306** ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
2307** <dd>The maximum depth of the parse tree on any expression.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002308**
drhd68eee02009-12-11 03:44:18 +00002309** ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
2310** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002311**
drhd68eee02009-12-11 03:44:18 +00002312** ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
drhbb4957f2008-03-20 14:03:29 +00002313** <dd>The maximum number of instructions in a virtual machine program
drhd68eee02009-12-11 03:44:18 +00002314** used to implement an SQL statement.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002315**
drhd68eee02009-12-11 03:44:18 +00002316** ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
2317** <dd>The maximum number of arguments on a function.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002318**
drhd68eee02009-12-11 03:44:18 +00002319** ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
drh46f33ef2009-02-11 15:23:35 +00002320** <dd>The maximum number of [ATTACH | attached databases].</dd>
drhbb4957f2008-03-20 14:03:29 +00002321**
drhd68eee02009-12-11 03:44:18 +00002322** ^<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
drh46f33ef2009-02-11 15:23:35 +00002323** <dd>The maximum length of the pattern argument to the [LIKE] or
drhd68eee02009-12-11 03:44:18 +00002324** [GLOB] operators.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002325**
drhd68eee02009-12-11 03:44:18 +00002326** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
drhbb4957f2008-03-20 14:03:29 +00002327** <dd>The maximum number of variables in an SQL statement that can
drhd68eee02009-12-11 03:44:18 +00002328** be bound.</dd>)^
drh417168a2009-09-07 18:14:02 +00002329**
drhd68eee02009-12-11 03:44:18 +00002330** ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
2331** <dd>The maximum depth of recursion for triggers.</dd>)^
drhbb4957f2008-03-20 14:03:29 +00002332** </dl>
drhcaa639f2008-03-20 00:32:20 +00002333*/
2334#define SQLITE_LIMIT_LENGTH 0
2335#define SQLITE_LIMIT_SQL_LENGTH 1
2336#define SQLITE_LIMIT_COLUMN 2
2337#define SQLITE_LIMIT_EXPR_DEPTH 3
2338#define SQLITE_LIMIT_COMPOUND_SELECT 4
2339#define SQLITE_LIMIT_VDBE_OP 5
2340#define SQLITE_LIMIT_FUNCTION_ARG 6
2341#define SQLITE_LIMIT_ATTACHED 7
drhb1a6c3c2008-03-20 16:30:17 +00002342#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
2343#define SQLITE_LIMIT_VARIABLE_NUMBER 9
drh417168a2009-09-07 18:14:02 +00002344#define SQLITE_LIMIT_TRIGGER_DEPTH 10
drhcaa639f2008-03-20 00:32:20 +00002345
2346/*
drhd68eee02009-12-11 03:44:18 +00002347** CAPI3REF: Compiling An SQL Statement
mihailimefc8e8a2008-06-21 16:47:09 +00002348** KEYWORDS: {SQL statement compiler}
danielk197765904932004-05-26 06:18:37 +00002349**
drh6ed48bf2007-06-14 20:57:18 +00002350** To execute an SQL query, it must first be compiled into a byte-code
mihailimefc8e8a2008-06-21 16:47:09 +00002351** program using one of these routines.
drh6ed48bf2007-06-14 20:57:18 +00002352**
mihailimefc8e8a2008-06-21 16:47:09 +00002353** The first argument, "db", is a [database connection] obtained from a
drh860e0772009-04-02 18:32:26 +00002354** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
2355** [sqlite3_open16()]. The database connection must not have been closed.
mihailimefc8e8a2008-06-21 16:47:09 +00002356**
2357** The second argument, "zSql", is the statement to be compiled, encoded
drh6ed48bf2007-06-14 20:57:18 +00002358** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
mihailimefc8e8a2008-06-21 16:47:09 +00002359** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
mihailim04bcc002008-06-22 10:21:27 +00002360** use UTF-16.
drh21f06722007-07-19 12:41:39 +00002361**
drhd68eee02009-12-11 03:44:18 +00002362** ^If the nByte argument is less than zero, then zSql is read up to the
2363** first zero terminator. ^If nByte is non-negative, then it is the maximum
2364** number of bytes read from zSql. ^When nByte is non-negative, the
mihailimefc8e8a2008-06-21 16:47:09 +00002365** zSql string ends at either the first '\000' or '\u0000' character or
drhb08c2a72008-04-16 00:28:13 +00002366** the nByte-th byte, whichever comes first. If the caller knows
danielk19773a2c8c82008-04-03 14:36:25 +00002367** that the supplied string is nul-terminated, then there is a small
mihailimefc8e8a2008-06-21 16:47:09 +00002368** performance advantage to be gained by passing an nByte parameter that
2369** is equal to the number of bytes in the input string <i>including</i>
mihailim04bcc002008-06-22 10:21:27 +00002370** the nul-terminator bytes.
danielk197765904932004-05-26 06:18:37 +00002371**
drhd68eee02009-12-11 03:44:18 +00002372** ^If pzTail is not NULL then *pzTail is made to point to the first byte
drh860e0772009-04-02 18:32:26 +00002373** past the end of the first SQL statement in zSql. These routines only
2374** compile the first statement in zSql, so *pzTail is left pointing to
2375** what remains uncompiled.
danielk197765904932004-05-26 06:18:37 +00002376**
drhd68eee02009-12-11 03:44:18 +00002377** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
2378** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
2379** to NULL. ^If the input text contains no SQL (if the input is an empty
mihailimefc8e8a2008-06-21 16:47:09 +00002380** string or a comment) then *ppStmt is set to NULL.
drh860e0772009-04-02 18:32:26 +00002381** The calling procedure is responsible for deleting the compiled
mihailimefc8e8a2008-06-21 16:47:09 +00002382** SQL statement using [sqlite3_finalize()] after it has finished with it.
drh860e0772009-04-02 18:32:26 +00002383** ppStmt may not be NULL.
danielk197765904932004-05-26 06:18:37 +00002384**
drhd68eee02009-12-11 03:44:18 +00002385** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
2386** otherwise an [error code] is returned.
drh6ed48bf2007-06-14 20:57:18 +00002387**
2388** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
2389** recommended for all new programs. The two older interfaces are retained
2390** for backwards compatibility, but their use is discouraged.
drhd68eee02009-12-11 03:44:18 +00002391** ^In the "v2" interfaces, the prepared statement
mihailimefc8e8a2008-06-21 16:47:09 +00002392** that is returned (the [sqlite3_stmt] object) contains a copy of the
mihailim04bcc002008-06-22 10:21:27 +00002393** original SQL text. This causes the [sqlite3_step()] interface to
drh481aa742009-11-05 18:46:02 +00002394** behave differently in three ways:
drh6ed48bf2007-06-14 20:57:18 +00002395**
2396** <ol>
drh33c1be32008-01-30 16:16:14 +00002397** <li>
drhd68eee02009-12-11 03:44:18 +00002398** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
drh6ed48bf2007-06-14 20:57:18 +00002399** always used to do, [sqlite3_step()] will automatically recompile the SQL
drhd68eee02009-12-11 03:44:18 +00002400** statement and try to run it again. ^If the schema has changed in
drhfddfa2d2007-12-05 18:05:16 +00002401** a way that makes the statement no longer valid, [sqlite3_step()] will still
mihailimefc8e8a2008-06-21 16:47:09 +00002402** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is
2403** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the
drh33c1be32008-01-30 16:16:14 +00002404** error go away. Note: use [sqlite3_errmsg()] to find the text
mihailim04bcc002008-06-22 10:21:27 +00002405** of the parsing error that results in an [SQLITE_SCHEMA] return.
drh6ed48bf2007-06-14 20:57:18 +00002406** </li>
2407**
2408** <li>
drhd68eee02009-12-11 03:44:18 +00002409** ^When an error occurs, [sqlite3_step()] will return one of the detailed
2410** [error codes] or [extended error codes]. ^The legacy behavior was that
mihailimefc8e8a2008-06-21 16:47:09 +00002411** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
2412** and you would have to make a second call to [sqlite3_reset()] in order
2413** to find the underlying cause of the problem. With the "v2" prepare
2414** interfaces, the underlying reason for the error is returned immediately.
drh6ed48bf2007-06-14 20:57:18 +00002415** </li>
drh4b5af772009-10-20 14:08:41 +00002416**
2417** <li>
2418** ^If the value of a [parameter | host parameter] in the WHERE clause might
2419** change the query plan for a statement, then the statement may be
2420** automatically recompiled (as if there had been a schema change) on the first
2421** [sqlite3_step()] call following any change to the
2422** [sqlite3_bind_text | bindings] of the [parameter].
2423** </li>
drh6ed48bf2007-06-14 20:57:18 +00002424** </ol>
danielk197765904932004-05-26 06:18:37 +00002425*/
2426int sqlite3_prepare(
2427 sqlite3 *db, /* Database handle */
2428 const char *zSql, /* SQL statement, UTF-8 encoded */
drh21f06722007-07-19 12:41:39 +00002429 int nByte, /* Maximum length of zSql in bytes. */
danielk197765904932004-05-26 06:18:37 +00002430 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2431 const char **pzTail /* OUT: Pointer to unused portion of zSql */
2432);
drh6ed48bf2007-06-14 20:57:18 +00002433int sqlite3_prepare_v2(
2434 sqlite3 *db, /* Database handle */
2435 const char *zSql, /* SQL statement, UTF-8 encoded */
drh21f06722007-07-19 12:41:39 +00002436 int nByte, /* Maximum length of zSql in bytes. */
drh6ed48bf2007-06-14 20:57:18 +00002437 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2438 const char **pzTail /* OUT: Pointer to unused portion of zSql */
2439);
danielk197765904932004-05-26 06:18:37 +00002440int sqlite3_prepare16(
2441 sqlite3 *db, /* Database handle */
2442 const void *zSql, /* SQL statement, UTF-16 encoded */
drh21f06722007-07-19 12:41:39 +00002443 int nByte, /* Maximum length of zSql in bytes. */
danielk197765904932004-05-26 06:18:37 +00002444 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2445 const void **pzTail /* OUT: Pointer to unused portion of zSql */
2446);
drhb900aaf2006-11-09 00:24:53 +00002447int sqlite3_prepare16_v2(
2448 sqlite3 *db, /* Database handle */
2449 const void *zSql, /* SQL statement, UTF-16 encoded */
drh21f06722007-07-19 12:41:39 +00002450 int nByte, /* Maximum length of zSql in bytes. */
drhb900aaf2006-11-09 00:24:53 +00002451 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2452 const void **pzTail /* OUT: Pointer to unused portion of zSql */
2453);
2454
2455/*
drhd68eee02009-12-11 03:44:18 +00002456** CAPI3REF: Retrieving Statement SQL
danielk1977d0e2a852007-11-14 06:48:48 +00002457**
drhd68eee02009-12-11 03:44:18 +00002458** ^This interface can be used to retrieve a saved copy of the original
mihailimefc8e8a2008-06-21 16:47:09 +00002459** SQL text used to create a [prepared statement] if that statement was
2460** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
danielk1977d0e2a852007-11-14 06:48:48 +00002461*/
2462const char *sqlite3_sql(sqlite3_stmt *pStmt);
2463
2464/*
drhd68eee02009-12-11 03:44:18 +00002465** CAPI3REF: Dynamically Typed Value Object
drhaa28e142008-03-18 13:47:20 +00002466** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
drh6ed48bf2007-06-14 20:57:18 +00002467**
drh33c1be32008-01-30 16:16:14 +00002468** SQLite uses the sqlite3_value object to represent all values
mihailimefc8e8a2008-06-21 16:47:09 +00002469** that can be stored in a database table. SQLite uses dynamic typing
drhd68eee02009-12-11 03:44:18 +00002470** for the values it stores. ^Values stored in sqlite3_value objects
mihailimefc8e8a2008-06-21 16:47:09 +00002471** can be integers, floating point values, strings, BLOBs, or NULL.
drhaa28e142008-03-18 13:47:20 +00002472**
2473** An sqlite3_value object may be either "protected" or "unprotected".
2474** Some interfaces require a protected sqlite3_value. Other interfaces
2475** will accept either a protected or an unprotected sqlite3_value.
mihailimefc8e8a2008-06-21 16:47:09 +00002476** Every interface that accepts sqlite3_value arguments specifies
drhaa28e142008-03-18 13:47:20 +00002477** whether or not it requires a protected sqlite3_value.
2478**
2479** The terms "protected" and "unprotected" refer to whether or not
2480** a mutex is held. A internal mutex is held for a protected
2481** sqlite3_value object but no mutex is held for an unprotected
2482** sqlite3_value object. If SQLite is compiled to be single-threaded
drh4766b292008-06-26 02:53:02 +00002483** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
drh4ead1482008-06-26 18:16:05 +00002484** or if SQLite is run in one of reduced mutex modes
2485** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
mihailimefc8e8a2008-06-21 16:47:09 +00002486** then there is no distinction between protected and unprotected
2487** sqlite3_value objects and they can be used interchangeably. However,
2488** for maximum code portability it is recommended that applications
2489** still make the distinction between between protected and unprotected
drh4ead1482008-06-26 18:16:05 +00002490** sqlite3_value objects even when not strictly required.
drhaa28e142008-03-18 13:47:20 +00002491**
drhd68eee02009-12-11 03:44:18 +00002492** ^The sqlite3_value objects that are passed as parameters into the
mihailimefc8e8a2008-06-21 16:47:09 +00002493** implementation of [application-defined SQL functions] are protected.
drhd68eee02009-12-11 03:44:18 +00002494** ^The sqlite3_value object returned by
drhaa28e142008-03-18 13:47:20 +00002495** [sqlite3_column_value()] is unprotected.
2496** Unprotected sqlite3_value objects may only be used with
mihailimefc8e8a2008-06-21 16:47:09 +00002497** [sqlite3_result_value()] and [sqlite3_bind_value()].
drhce5a5a02008-06-10 17:41:44 +00002498** The [sqlite3_value_blob | sqlite3_value_type()] family of
2499** interfaces require protected sqlite3_value objects.
drhf4479502004-05-27 03:12:53 +00002500*/
drhf4479502004-05-27 03:12:53 +00002501typedef struct Mem sqlite3_value;
2502
2503/*
drhb25f9d82008-07-23 15:40:06 +00002504** CAPI3REF: SQL Function Context Object {H16001} <S20200>
drh4f26d6c2004-05-26 23:25:30 +00002505**
drh6ed48bf2007-06-14 20:57:18 +00002506** The context in which an SQL function executes is stored in an
drhd68eee02009-12-11 03:44:18 +00002507** sqlite3_context object. ^A pointer to an sqlite3_context object
mihailimefc8e8a2008-06-21 16:47:09 +00002508** is always first parameter to [application-defined SQL functions].
2509** The application-defined SQL function implementation will pass this
2510** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
2511** [sqlite3_aggregate_context()], [sqlite3_user_data()],
2512** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
2513** and/or [sqlite3_set_auxdata()].
drh6ed48bf2007-06-14 20:57:18 +00002514*/
2515typedef struct sqlite3_context sqlite3_context;
2516
2517/*
drhb25f9d82008-07-23 15:40:06 +00002518** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300>
mihailimefc8e8a2008-06-21 16:47:09 +00002519** KEYWORDS: {host parameter} {host parameters} {host parameter name}
mihailimebe796c2008-06-21 20:11:17 +00002520** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
drh6ed48bf2007-06-14 20:57:18 +00002521**
drhd68eee02009-12-11 03:44:18 +00002522** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
drh333ceb92009-08-25 14:59:37 +00002523** literals may be replaced by a [parameter] that matches one of following
2524** templates:
drh6ed48bf2007-06-14 20:57:18 +00002525**
2526** <ul>
2527** <li> ?
2528** <li> ?NNN
drh33c1be32008-01-30 16:16:14 +00002529** <li> :VVV
2530** <li> @VVV
drh6ed48bf2007-06-14 20:57:18 +00002531** <li> $VVV
2532** </ul>
2533**
drh333ceb92009-08-25 14:59:37 +00002534** In the templates above, NNN represents an integer literal,
drhd68eee02009-12-11 03:44:18 +00002535** and VVV represents an alphanumeric identifer.)^ ^The values of these
mihailimefc8e8a2008-06-21 16:47:09 +00002536** parameters (also called "host parameter names" or "SQL parameters")
drh6ed48bf2007-06-14 20:57:18 +00002537** can be set using the sqlite3_bind_*() routines defined here.
2538**
drhd68eee02009-12-11 03:44:18 +00002539** ^The first argument to the sqlite3_bind_*() routines is always
mihailimefc8e8a2008-06-21 16:47:09 +00002540** a pointer to the [sqlite3_stmt] object returned from
2541** [sqlite3_prepare_v2()] or its variants.
2542**
drhd68eee02009-12-11 03:44:18 +00002543** ^The second argument is the index of the SQL parameter to be set.
2544** ^The leftmost SQL parameter has an index of 1. ^When the same named
mihailimefc8e8a2008-06-21 16:47:09 +00002545** SQL parameter is used more than once, second and subsequent
2546** occurrences have the same index as the first occurrence.
drhd68eee02009-12-11 03:44:18 +00002547** ^The index for named parameters can be looked up using the
2548** [sqlite3_bind_parameter_index()] API if desired. ^The index
drhf5befa02007-12-06 02:42:07 +00002549** for "?NNN" parameters is the value of NNN.
drhd68eee02009-12-11 03:44:18 +00002550** ^The NNN value must be between 1 and the [sqlite3_limit()]
drh4ead1482008-06-26 18:16:05 +00002551** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
drh6ed48bf2007-06-14 20:57:18 +00002552**
drhd68eee02009-12-11 03:44:18 +00002553** ^The third argument is the value to bind to the parameter.
drh6ed48bf2007-06-14 20:57:18 +00002554**
drhd68eee02009-12-11 03:44:18 +00002555** ^(In those routines that have a fourth argument, its value is the
mihailimefc8e8a2008-06-21 16:47:09 +00002556** number of bytes in the parameter. To be clear: the value is the
drhd68eee02009-12-11 03:44:18 +00002557** number of <u>bytes</u> in the value, not the number of characters.)^
2558** ^If the fourth parameter is negative, the length of the string is
shane26b34032008-05-23 17:21:09 +00002559** the number of bytes up to the first zero terminator.
drh4f26d6c2004-05-26 23:25:30 +00002560**
drhd68eee02009-12-11 03:44:18 +00002561** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
drh900dfba2004-07-21 15:21:36 +00002562** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
drhd68eee02009-12-11 03:44:18 +00002563** string after SQLite has finished with it. ^If the fifth argument is
drh33c1be32008-01-30 16:16:14 +00002564** the special value [SQLITE_STATIC], then SQLite assumes that the
drhfddfa2d2007-12-05 18:05:16 +00002565** information is in static, unmanaged space and does not need to be freed.
drhd68eee02009-12-11 03:44:18 +00002566** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
drhfddfa2d2007-12-05 18:05:16 +00002567** SQLite makes its own private copy of the data immediately, before
drh33c1be32008-01-30 16:16:14 +00002568** the sqlite3_bind_*() routine returns.
drh4f26d6c2004-05-26 23:25:30 +00002569**
drhd68eee02009-12-11 03:44:18 +00002570** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
2571** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
mihailimefc8e8a2008-06-21 16:47:09 +00002572** (just an integer to hold its size) while it is being processed.
shane26b34032008-05-23 17:21:09 +00002573** Zeroblobs are intended to serve as placeholders for BLOBs whose
mihailimefc8e8a2008-06-21 16:47:09 +00002574** content is later written using
2575** [sqlite3_blob_open | incremental BLOB I/O] routines.
drhd68eee02009-12-11 03:44:18 +00002576** ^A negative value for the zeroblob results in a zero-length BLOB.
drh6ed48bf2007-06-14 20:57:18 +00002577**
drhd68eee02009-12-11 03:44:18 +00002578** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
2579** for the [prepared statement] or with a prepared statement for which
2580** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
2581** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
2582** routine is passed a [prepared statement] that has been finalized, the
2583** result is undefined and probably harmful.
drh6ed48bf2007-06-14 20:57:18 +00002584**
drhd68eee02009-12-11 03:44:18 +00002585** ^Bindings are not cleared by the [sqlite3_reset()] routine.
2586** ^Unbound parameters are interpreted as NULL.
2587**
2588** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
2589** [error code] if anything goes wrong.
2590** ^[SQLITE_RANGE] is returned if the parameter
2591** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
drh33c1be32008-01-30 16:16:14 +00002592**
2593** See also: [sqlite3_bind_parameter_count()],
mihailimefc8e8a2008-06-21 16:47:09 +00002594** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
drh4f26d6c2004-05-26 23:25:30 +00002595*/
danielk1977d8123362004-06-12 09:25:12 +00002596int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
drhf4479502004-05-27 03:12:53 +00002597int sqlite3_bind_double(sqlite3_stmt*, int, double);
2598int sqlite3_bind_int(sqlite3_stmt*, int, int);
drh6d2069d2007-08-14 01:58:53 +00002599int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
drhf4479502004-05-27 03:12:53 +00002600int sqlite3_bind_null(sqlite3_stmt*, int);
danielk1977d8123362004-06-12 09:25:12 +00002601int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
2602int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
drhf4479502004-05-27 03:12:53 +00002603int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
drhb026e052007-05-02 01:34:31 +00002604int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
drh4f26d6c2004-05-26 23:25:30 +00002605
2606/*
drhd68eee02009-12-11 03:44:18 +00002607** CAPI3REF: Number Of SQL Parameters
drh6ed48bf2007-06-14 20:57:18 +00002608**
drhd68eee02009-12-11 03:44:18 +00002609** ^This routine can be used to find the number of [SQL parameters]
mihailimefc8e8a2008-06-21 16:47:09 +00002610** in a [prepared statement]. SQL parameters are tokens of the
drh33c1be32008-01-30 16:16:14 +00002611** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
shane26b34032008-05-23 17:21:09 +00002612** placeholders for values that are [sqlite3_bind_blob | bound]
drh33c1be32008-01-30 16:16:14 +00002613** to the parameters at a later time.
drh605264d2007-08-21 15:13:19 +00002614**
drhd68eee02009-12-11 03:44:18 +00002615** ^(This routine actually returns the index of the largest (rightmost)
mihailimefc8e8a2008-06-21 16:47:09 +00002616** parameter. For all forms except ?NNN, this will correspond to the
drhd68eee02009-12-11 03:44:18 +00002617** number of unique parameters. If parameters of the ?NNN form are used,
2618** there may be gaps in the list.)^
drh33c1be32008-01-30 16:16:14 +00002619**
2620** See also: [sqlite3_bind_blob|sqlite3_bind()],
2621** [sqlite3_bind_parameter_name()], and
2622** [sqlite3_bind_parameter_index()].
drh75f6a032004-07-15 14:15:00 +00002623*/
2624int sqlite3_bind_parameter_count(sqlite3_stmt*);
2625
2626/*
drhd68eee02009-12-11 03:44:18 +00002627** CAPI3REF: Name Of A Host Parameter
drh6ed48bf2007-06-14 20:57:18 +00002628**
drhd68eee02009-12-11 03:44:18 +00002629** ^The sqlite3_bind_parameter_name(P,N) interface returns
2630** the name of the N-th [SQL parameter] in the [prepared statement] P.
2631** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
drhe1b3e802008-04-27 22:29:01 +00002632** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
2633** respectively.
2634** In other words, the initial ":" or "$" or "@" or "?"
drhd68eee02009-12-11 03:44:18 +00002635** is included as part of the name.)^
2636** ^Parameters of the form "?" without a following integer have no name
2637** and are also referred to as "nameless" or "anonymous parameters".
drh6ed48bf2007-06-14 20:57:18 +00002638**
drhd68eee02009-12-11 03:44:18 +00002639** ^The first host parameter has an index of 1, not 0.
drh6ed48bf2007-06-14 20:57:18 +00002640**
drhd68eee02009-12-11 03:44:18 +00002641** ^If the value N is out of range or if the N-th parameter is
2642** nameless, then NULL is returned. ^The returned string is
mihailimefc8e8a2008-06-21 16:47:09 +00002643** always in UTF-8 encoding even if the named parameter was
drhfddfa2d2007-12-05 18:05:16 +00002644** originally specified as UTF-16 in [sqlite3_prepare16()] or
2645** [sqlite3_prepare16_v2()].
drh33c1be32008-01-30 16:16:14 +00002646**
2647** See also: [sqlite3_bind_blob|sqlite3_bind()],
2648** [sqlite3_bind_parameter_count()], and
2649** [sqlite3_bind_parameter_index()].
drh895d7472004-08-20 16:02:39 +00002650*/
2651const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
2652
2653/*
drhd68eee02009-12-11 03:44:18 +00002654** CAPI3REF: Index Of A Parameter With A Given Name
drh6ed48bf2007-06-14 20:57:18 +00002655**
drhd68eee02009-12-11 03:44:18 +00002656** ^Return the index of an SQL parameter given its name. ^The
drh33c1be32008-01-30 16:16:14 +00002657** index value returned is suitable for use as the second
drhd68eee02009-12-11 03:44:18 +00002658** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
2659** is returned if no matching parameter is found. ^The parameter
drh33c1be32008-01-30 16:16:14 +00002660** name must be given in UTF-8 even if the original statement
2661** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
2662**
2663** See also: [sqlite3_bind_blob|sqlite3_bind()],
2664** [sqlite3_bind_parameter_count()], and
2665** [sqlite3_bind_parameter_index()].
drhfa6bc002004-09-07 16:19:52 +00002666*/
2667int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
2668
2669/*
drhd68eee02009-12-11 03:44:18 +00002670** CAPI3REF: Reset All Bindings On A Prepared Statement
drh6ed48bf2007-06-14 20:57:18 +00002671**
drhd68eee02009-12-11 03:44:18 +00002672** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
mihailimefc8e8a2008-06-21 16:47:09 +00002673** the [sqlite3_bind_blob | bindings] on a [prepared statement].
drhd68eee02009-12-11 03:44:18 +00002674** ^Use this routine to reset all host parameters to NULL.
danielk1977600dd0b2005-01-20 01:14:23 +00002675*/
2676int sqlite3_clear_bindings(sqlite3_stmt*);
2677
2678/*
drhd68eee02009-12-11 03:44:18 +00002679** CAPI3REF: Number Of Columns In A Result Set
drh6ed48bf2007-06-14 20:57:18 +00002680**
drhd68eee02009-12-11 03:44:18 +00002681** ^Return the number of columns in the result set returned by the
2682** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
drh4ead1482008-06-26 18:16:05 +00002683** statement that does not return data (for example an [UPDATE]).
danielk197765904932004-05-26 06:18:37 +00002684*/
2685int sqlite3_column_count(sqlite3_stmt *pStmt);
2686
2687/*
drhd68eee02009-12-11 03:44:18 +00002688** CAPI3REF: Column Names In A Result Set
drh6ed48bf2007-06-14 20:57:18 +00002689**
drhd68eee02009-12-11 03:44:18 +00002690** ^These routines return the name assigned to a particular column
2691** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
mihailimefc8e8a2008-06-21 16:47:09 +00002692** interface returns a pointer to a zero-terminated UTF-8 string
drhf5befa02007-12-06 02:42:07 +00002693** and sqlite3_column_name16() returns a pointer to a zero-terminated
drhd68eee02009-12-11 03:44:18 +00002694** UTF-16 string. ^The first parameter is the [prepared statement]
2695** that implements the [SELECT] statement. ^The second parameter is the
2696** column number. ^The leftmost column is number 0.
drh6ed48bf2007-06-14 20:57:18 +00002697**
drhd68eee02009-12-11 03:44:18 +00002698** ^The returned string pointer is valid until either the [prepared statement]
mihailimefc8e8a2008-06-21 16:47:09 +00002699** is destroyed by [sqlite3_finalize()] or until the next call to
2700** sqlite3_column_name() or sqlite3_column_name16() on the same column.
drh4a50aac2007-08-23 02:47:53 +00002701**
drhd68eee02009-12-11 03:44:18 +00002702** ^If sqlite3_malloc() fails during the processing of either routine
drh4a50aac2007-08-23 02:47:53 +00002703** (for example during a conversion from UTF-8 to UTF-16) then a
2704** NULL pointer is returned.
drh33c1be32008-01-30 16:16:14 +00002705**
drhd68eee02009-12-11 03:44:18 +00002706** ^The name of a result column is the value of the "AS" clause for
drh33c1be32008-01-30 16:16:14 +00002707** that column, if there is an AS clause. If there is no AS clause
2708** then the name of the column is unspecified and may change from
2709** one release of SQLite to the next.
danielk197765904932004-05-26 06:18:37 +00002710*/
drh6ed48bf2007-06-14 20:57:18 +00002711const char *sqlite3_column_name(sqlite3_stmt*, int N);
2712const void *sqlite3_column_name16(sqlite3_stmt*, int N);
danielk197765904932004-05-26 06:18:37 +00002713
2714/*
drhd68eee02009-12-11 03:44:18 +00002715** CAPI3REF: Source Of Data In A Query Result
drh6ed48bf2007-06-14 20:57:18 +00002716**
drhd68eee02009-12-11 03:44:18 +00002717** ^These routines provide a means to determine what column of what
drh4ead1482008-06-26 18:16:05 +00002718** table in which database a result of a [SELECT] statement comes from.
drhd68eee02009-12-11 03:44:18 +00002719** ^The name of the database or table or column can be returned as
2720** either a UTF-8 or UTF-16 string. ^The _database_ routines return
drhbf2564f2007-06-21 15:25:05 +00002721** the database name, the _table_ routines return the table name, and
drh33c1be32008-01-30 16:16:14 +00002722** the origin_ routines return the column name.
drhd68eee02009-12-11 03:44:18 +00002723** ^The returned string is valid until the [prepared statement] is destroyed
mihailim1c492652008-06-21 18:02:16 +00002724** using [sqlite3_finalize()] or until the same information is requested
drhbf2564f2007-06-21 15:25:05 +00002725** again in a different encoding.
2726**
drhd68eee02009-12-11 03:44:18 +00002727** ^The names returned are the original un-aliased names of the
drhbf2564f2007-06-21 15:25:05 +00002728** database, table, and column.
drh6ed48bf2007-06-14 20:57:18 +00002729**
drhd68eee02009-12-11 03:44:18 +00002730** ^The first argument these interfaces is a [prepared statement].
2731** ^These functions return information about the Nth column returned by
danielk1977955de522006-02-10 02:27:42 +00002732** the statement, where N is the second function argument.
drhd68eee02009-12-11 03:44:18 +00002733** ^The left-most column is column 0 for these interface.
danielk1977955de522006-02-10 02:27:42 +00002734**
drhd68eee02009-12-11 03:44:18 +00002735** ^If the Nth column returned by the statement is an expression or
mihailim1c492652008-06-21 18:02:16 +00002736** subquery and is not a column value, then all of these functions return
drhd68eee02009-12-11 03:44:18 +00002737** NULL. ^These routine might also return NULL if a memory allocation error
2738** occurs. ^Otherwise, they return the name of the attached database, table
2739** or column that query result column was extracted from.
danielk1977955de522006-02-10 02:27:42 +00002740**
drhd68eee02009-12-11 03:44:18 +00002741** ^As with all other SQLite APIs, those postfixed with "16" return
2742** UTF-16 encoded strings, the other functions return UTF-8.
danielk19774b1ae992006-02-10 03:06:10 +00002743**
drhd68eee02009-12-11 03:44:18 +00002744** ^These APIs are only available if the library was compiled with the
drh4ead1482008-06-26 18:16:05 +00002745** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
drh32bc3f62007-08-21 20:25:39 +00002746**
2747** If two or more threads call one or more of these routines against the same
2748** prepared statement and column at the same time then the results are
2749** undefined.
drh33c1be32008-01-30 16:16:14 +00002750**
drh8b39db12009-02-18 18:37:58 +00002751** If two or more threads call one or more
2752** [sqlite3_column_database_name | column metadata interfaces]
2753** for the same [prepared statement] and result column
2754** at the same time then the results are undefined.
danielk1977955de522006-02-10 02:27:42 +00002755*/
2756const char *sqlite3_column_database_name(sqlite3_stmt*,int);
2757const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
2758const char *sqlite3_column_table_name(sqlite3_stmt*,int);
2759const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
2760const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
2761const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
2762
2763/*
drhd68eee02009-12-11 03:44:18 +00002764** CAPI3REF: Declared Datatype Of A Query Result
drh6ed48bf2007-06-14 20:57:18 +00002765**
drhd68eee02009-12-11 03:44:18 +00002766** ^(The first parameter is a [prepared statement].
drh4ead1482008-06-26 18:16:05 +00002767** If this statement is a [SELECT] statement and the Nth column of the
2768** returned result set of that [SELECT] is a table column (not an
drh6ed48bf2007-06-14 20:57:18 +00002769** expression or subquery) then the declared type of the table
drhd68eee02009-12-11 03:44:18 +00002770** column is returned.) ^If the Nth column of the result set is an
drh6ed48bf2007-06-14 20:57:18 +00002771** expression or subquery, then a NULL pointer is returned.
drhd68eee02009-12-11 03:44:18 +00002772** ^The returned string is always UTF-8 encoded.
mihailim1c492652008-06-21 18:02:16 +00002773**
drhd68eee02009-12-11 03:44:18 +00002774** ^(For example, given the database schema:
danielk197765904932004-05-26 06:18:37 +00002775**
2776** CREATE TABLE t1(c1 VARIANT);
2777**
mihailim1c492652008-06-21 18:02:16 +00002778** and the following statement to be compiled:
danielk197765904932004-05-26 06:18:37 +00002779**
danielk1977955de522006-02-10 02:27:42 +00002780** SELECT c1 + 1, c1 FROM t1;
danielk197765904932004-05-26 06:18:37 +00002781**
mihailim1c492652008-06-21 18:02:16 +00002782** this routine would return the string "VARIANT" for the second result
drhd68eee02009-12-11 03:44:18 +00002783** column (i==1), and a NULL pointer for the first result column (i==0).)^
drh6ed48bf2007-06-14 20:57:18 +00002784**
drhd68eee02009-12-11 03:44:18 +00002785** ^SQLite uses dynamic run-time typing. ^So just because a column
drh6ed48bf2007-06-14 20:57:18 +00002786** is declared to contain a particular type does not mean that the
2787** data stored in that column is of the declared type. SQLite is
drhd68eee02009-12-11 03:44:18 +00002788** strongly typed, but the typing is dynamic not static. ^Type
drh6ed48bf2007-06-14 20:57:18 +00002789** is associated with individual values, not with the containers
2790** used to hold those values.
danielk197765904932004-05-26 06:18:37 +00002791*/
drh33c1be32008-01-30 16:16:14 +00002792const char *sqlite3_column_decltype(sqlite3_stmt*,int);
danielk197765904932004-05-26 06:18:37 +00002793const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
2794
mihailimebe796c2008-06-21 20:11:17 +00002795/*
drhd68eee02009-12-11 03:44:18 +00002796** CAPI3REF: Evaluate An SQL Statement
danielk1977106bb232004-05-21 10:08:53 +00002797**
mihailim1c492652008-06-21 18:02:16 +00002798** After a [prepared statement] has been prepared using either
2799** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
2800** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
2801** must be called one or more times to evaluate the statement.
danielk1977106bb232004-05-21 10:08:53 +00002802**
mihailim1c492652008-06-21 18:02:16 +00002803** The details of the behavior of the sqlite3_step() interface depend
drh6ed48bf2007-06-14 20:57:18 +00002804** on whether the statement was prepared using the newer "v2" interface
2805** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
2806** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
2807** new "v2" interface is recommended for new applications but the legacy
2808** interface will continue to be supported.
danielk1977106bb232004-05-21 10:08:53 +00002809**
drhd68eee02009-12-11 03:44:18 +00002810** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
drh6ed48bf2007-06-14 20:57:18 +00002811** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
drhd68eee02009-12-11 03:44:18 +00002812** ^With the "v2" interface, any of the other [result codes] or
mihailim1c492652008-06-21 18:02:16 +00002813** [extended result codes] might be returned as well.
drh6ed48bf2007-06-14 20:57:18 +00002814**
drhd68eee02009-12-11 03:44:18 +00002815** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
2816** database locks it needs to do its job. ^If the statement is a [COMMIT]
drh6ed48bf2007-06-14 20:57:18 +00002817** or occurs outside of an explicit transaction, then you can retry the
drh4ead1482008-06-26 18:16:05 +00002818** statement. If the statement is not a [COMMIT] and occurs within a
drh6ed48bf2007-06-14 20:57:18 +00002819** explicit transaction then you should rollback the transaction before
2820** continuing.
2821**
drhd68eee02009-12-11 03:44:18 +00002822** ^[SQLITE_DONE] means that the statement has finished executing
danielk1977106bb232004-05-21 10:08:53 +00002823** successfully. sqlite3_step() should not be called again on this virtual
drh6ed48bf2007-06-14 20:57:18 +00002824** machine without first calling [sqlite3_reset()] to reset the virtual
2825** machine back to its initial state.
danielk1977106bb232004-05-21 10:08:53 +00002826**
drhd68eee02009-12-11 03:44:18 +00002827** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
mihailim1c492652008-06-21 18:02:16 +00002828** is returned each time a new row of data is ready for processing by the
2829** caller. The values may be accessed using the [column access functions].
drh6ed48bf2007-06-14 20:57:18 +00002830** sqlite3_step() is called again to retrieve the next row of data.
mihailim1c492652008-06-21 18:02:16 +00002831**
drhd68eee02009-12-11 03:44:18 +00002832** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
danielk1977106bb232004-05-21 10:08:53 +00002833** violation) has occurred. sqlite3_step() should not be called again on
drh6ed48bf2007-06-14 20:57:18 +00002834** the VM. More information may be found by calling [sqlite3_errmsg()].
drhd68eee02009-12-11 03:44:18 +00002835** ^With the legacy interface, a more specific error code (for example,
drh6ed48bf2007-06-14 20:57:18 +00002836** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
2837** can be obtained by calling [sqlite3_reset()] on the
drhd68eee02009-12-11 03:44:18 +00002838** [prepared statement]. ^In the "v2" interface,
drh6ed48bf2007-06-14 20:57:18 +00002839** the more specific error code is returned directly by sqlite3_step().
danielk1977106bb232004-05-21 10:08:53 +00002840**
drh6ed48bf2007-06-14 20:57:18 +00002841** [SQLITE_MISUSE] means that the this routine was called inappropriately.
drh33c1be32008-01-30 16:16:14 +00002842** Perhaps it was called on a [prepared statement] that has
mihailim1c492652008-06-21 18:02:16 +00002843** already been [sqlite3_finalize | finalized] or on one that had
drh6ed48bf2007-06-14 20:57:18 +00002844** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
2845** be the case that the same database connection is being used by two or
2846** more threads at the same moment in time.
2847**
mihailim1c492652008-06-21 18:02:16 +00002848** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
2849** API always returns a generic error code, [SQLITE_ERROR], following any
2850** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
2851** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
2852** specific [error codes] that better describes the error.
drh6ed48bf2007-06-14 20:57:18 +00002853** We admit that this is a goofy design. The problem has been fixed
2854** with the "v2" interface. If you prepare all of your SQL statements
2855** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
mihailim1c492652008-06-21 18:02:16 +00002856** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
2857** then the more specific [error codes] are returned directly
drh6ed48bf2007-06-14 20:57:18 +00002858** by sqlite3_step(). The use of the "v2" interface is recommended.
danielk1977106bb232004-05-21 10:08:53 +00002859*/
danielk197717240fd2004-05-26 00:07:25 +00002860int sqlite3_step(sqlite3_stmt*);
danielk1977106bb232004-05-21 10:08:53 +00002861
danielk1977106bb232004-05-21 10:08:53 +00002862/*
drhd68eee02009-12-11 03:44:18 +00002863** CAPI3REF: Number of columns in a result set
drh6ed48bf2007-06-14 20:57:18 +00002864**
drhd68eee02009-12-11 03:44:18 +00002865** ^Returns the number of values in the current row of the result set.
danielk1977106bb232004-05-21 10:08:53 +00002866*/
danielk197793d46752004-05-23 13:30:58 +00002867int sqlite3_data_count(sqlite3_stmt *pStmt);
danielk19774adee202004-05-08 08:23:19 +00002868
drh4f26d6c2004-05-26 23:25:30 +00002869/*
drhd68eee02009-12-11 03:44:18 +00002870** CAPI3REF: Fundamental Datatypes
drh33c1be32008-01-30 16:16:14 +00002871** KEYWORDS: SQLITE_TEXT
drh6ed48bf2007-06-14 20:57:18 +00002872**
drh9a247912008-07-22 18:45:08 +00002873** {H10266} Every value in SQLite has one of five fundamental datatypes:
drh6ed48bf2007-06-14 20:57:18 +00002874**
2875** <ul>
2876** <li> 64-bit signed integer
2877** <li> 64-bit IEEE floating point number
2878** <li> string
2879** <li> BLOB
2880** <li> NULL
drhfddfa2d2007-12-05 18:05:16 +00002881** </ul> {END}
drh6ed48bf2007-06-14 20:57:18 +00002882**
2883** These constants are codes for each of those types.
2884**
2885** Note that the SQLITE_TEXT constant was also used in SQLite version 2
2886** for a completely different meaning. Software that links against both
mihailim1c492652008-06-21 18:02:16 +00002887** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
drh6ed48bf2007-06-14 20:57:18 +00002888** SQLITE_TEXT.
drh4f26d6c2004-05-26 23:25:30 +00002889*/
drh9c054832004-05-31 18:51:57 +00002890#define SQLITE_INTEGER 1
2891#define SQLITE_FLOAT 2
drh9c054832004-05-31 18:51:57 +00002892#define SQLITE_BLOB 4
2893#define SQLITE_NULL 5
drh1e284f42004-10-06 15:52:01 +00002894#ifdef SQLITE_TEXT
2895# undef SQLITE_TEXT
2896#else
2897# define SQLITE_TEXT 3
2898#endif
2899#define SQLITE3_TEXT 3
2900
2901/*
drhd68eee02009-12-11 03:44:18 +00002902** CAPI3REF: Result Values From A Query
mihailim1c492652008-06-21 18:02:16 +00002903** KEYWORDS: {column access functions}
drh6ed48bf2007-06-14 20:57:18 +00002904**
drhd68eee02009-12-11 03:44:18 +00002905** These routines form the "result set" interface.
drh33c1be32008-01-30 16:16:14 +00002906**
drhd68eee02009-12-11 03:44:18 +00002907** ^These routines return information about a single column of the current
2908** result row of a query. ^In every case the first argument is a pointer
mihailim1c492652008-06-21 18:02:16 +00002909** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
2910** that was returned from [sqlite3_prepare_v2()] or one of its variants)
2911** and the second argument is the index of the column for which information
drhd68eee02009-12-11 03:44:18 +00002912** should be returned. ^The leftmost column of the result set has the index 0.
2913** ^The number of columns in the result can be determined using
drhedc17552009-10-22 00:14:05 +00002914** [sqlite3_column_count()].
danielk1977106bb232004-05-21 10:08:53 +00002915**
mihailim1c492652008-06-21 18:02:16 +00002916** If the SQL statement does not currently point to a valid row, or if the
2917** column index is out of range, the result is undefined.
drh32bc3f62007-08-21 20:25:39 +00002918** These routines may only be called when the most recent call to
2919** [sqlite3_step()] has returned [SQLITE_ROW] and neither
mihailim1c492652008-06-21 18:02:16 +00002920** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
drh32bc3f62007-08-21 20:25:39 +00002921** If any of these routines are called after [sqlite3_reset()] or
2922** [sqlite3_finalize()] or after [sqlite3_step()] has returned
2923** something other than [SQLITE_ROW], the results are undefined.
2924** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
2925** are called from a different thread while any of these routines
mihailim1c492652008-06-21 18:02:16 +00002926** are pending, then the results are undefined.
drh6ed48bf2007-06-14 20:57:18 +00002927**
drhd68eee02009-12-11 03:44:18 +00002928** ^The sqlite3_column_type() routine returns the
drh6ed48bf2007-06-14 20:57:18 +00002929** [SQLITE_INTEGER | datatype code] for the initial data type
drhd68eee02009-12-11 03:44:18 +00002930** of the result column. ^The returned value is one of [SQLITE_INTEGER],
drh6ed48bf2007-06-14 20:57:18 +00002931** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
2932** returned by sqlite3_column_type() is only meaningful if no type
2933** conversions have occurred as described below. After a type conversion,
2934** the value returned by sqlite3_column_type() is undefined. Future
2935** versions of SQLite may change the behavior of sqlite3_column_type()
2936** following a type conversion.
2937**
drhd68eee02009-12-11 03:44:18 +00002938** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
drh6ed48bf2007-06-14 20:57:18 +00002939** routine returns the number of bytes in that BLOB or string.
drhd68eee02009-12-11 03:44:18 +00002940** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
drh6ed48bf2007-06-14 20:57:18 +00002941** the string to UTF-8 and then returns the number of bytes.
drhd68eee02009-12-11 03:44:18 +00002942** ^If the result is a numeric value then sqlite3_column_bytes() uses
mihailimebe796c2008-06-21 20:11:17 +00002943** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
drh6ed48bf2007-06-14 20:57:18 +00002944** the number of bytes in that string.
drhd68eee02009-12-11 03:44:18 +00002945** ^The value returned does not include the zero terminator at the end
2946** of the string. ^For clarity: the value returned is the number of
drh6ed48bf2007-06-14 20:57:18 +00002947** bytes in the string, not the number of characters.
2948**
drhd68eee02009-12-11 03:44:18 +00002949** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
2950** even empty strings, are always zero terminated. ^The return
mihailim04bcc002008-06-22 10:21:27 +00002951** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary
drhc0b3abb2007-09-04 12:18:41 +00002952** pointer, possibly even a NULL pointer.
2953**
drhd68eee02009-12-11 03:44:18 +00002954** ^The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
mihailim1c492652008-06-21 18:02:16 +00002955** but leaves the result in UTF-16 in native byte order instead of UTF-8.
drhd68eee02009-12-11 03:44:18 +00002956** ^The zero terminator is not included in this count.
drh4f26d6c2004-05-26 23:25:30 +00002957**
drhd68eee02009-12-11 03:44:18 +00002958** ^The object returned by [sqlite3_column_value()] is an
drhaa28e142008-03-18 13:47:20 +00002959** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
2960** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
2961** If the [unprotected sqlite3_value] object returned by
2962** [sqlite3_column_value()] is used in any other way, including calls
mihailim1c492652008-06-21 18:02:16 +00002963** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
2964** or [sqlite3_value_bytes()], then the behavior is undefined.
drhaa28e142008-03-18 13:47:20 +00002965**
drhd68eee02009-12-11 03:44:18 +00002966** These routines attempt to convert the value where appropriate. ^For
drh4f26d6c2004-05-26 23:25:30 +00002967** example, if the internal representation is FLOAT and a text result
mihailim1c492652008-06-21 18:02:16 +00002968** is requested, [sqlite3_snprintf()] is used internally to perform the
drhd68eee02009-12-11 03:44:18 +00002969** conversion automatically. ^(The following table details the conversions
mihailim1c492652008-06-21 18:02:16 +00002970** that are applied:
drh4f26d6c2004-05-26 23:25:30 +00002971**
drh6ed48bf2007-06-14 20:57:18 +00002972** <blockquote>
2973** <table border="1">
drh8bacf972007-08-25 16:21:29 +00002974** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
drh4f26d6c2004-05-26 23:25:30 +00002975**
drh6ed48bf2007-06-14 20:57:18 +00002976** <tr><td> NULL <td> INTEGER <td> Result is 0
2977** <tr><td> NULL <td> FLOAT <td> Result is 0.0
2978** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
2979** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
2980** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
2981** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
mihailim1c492652008-06-21 18:02:16 +00002982** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
drh6ed48bf2007-06-14 20:57:18 +00002983** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
2984** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
2985** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
2986** <tr><td> TEXT <td> INTEGER <td> Use atoi()
2987** <tr><td> TEXT <td> FLOAT <td> Use atof()
2988** <tr><td> TEXT <td> BLOB <td> No change
2989** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
2990** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
2991** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
2992** </table>
drhd68eee02009-12-11 03:44:18 +00002993** </blockquote>)^
drh4f26d6c2004-05-26 23:25:30 +00002994**
drh6ed48bf2007-06-14 20:57:18 +00002995** The table above makes reference to standard C library functions atoi()
2996** and atof(). SQLite does not really use these functions. It has its
shane26b34032008-05-23 17:21:09 +00002997** own equivalent internal routines. The atoi() and atof() names are
drh6ed48bf2007-06-14 20:57:18 +00002998** used in the table for brevity and because they are familiar to most
2999** C programmers.
3000**
drhd68eee02009-12-11 03:44:18 +00003001** ^Note that when type conversions occur, pointers returned by prior
drh6ed48bf2007-06-14 20:57:18 +00003002** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
mihailim1c492652008-06-21 18:02:16 +00003003** sqlite3_column_text16() may be invalidated.
drhd68eee02009-12-11 03:44:18 +00003004** ^(Type conversions and pointer invalidations might occur
drh6ed48bf2007-06-14 20:57:18 +00003005** in the following cases:
3006**
3007** <ul>
mihailim1c492652008-06-21 18:02:16 +00003008** <li> The initial content is a BLOB and sqlite3_column_text() or
3009** sqlite3_column_text16() is called. A zero-terminator might
3010** need to be added to the string.</li>
3011** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3012** sqlite3_column_text16() is called. The content must be converted
3013** to UTF-16.</li>
3014** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3015** sqlite3_column_text() is called. The content must be converted
3016** to UTF-8.</li>
drhd68eee02009-12-11 03:44:18 +00003017** </ul>)^
drh6ed48bf2007-06-14 20:57:18 +00003018**
drhd68eee02009-12-11 03:44:18 +00003019** ^Conversions between UTF-16be and UTF-16le are always done in place and do
drh6ed48bf2007-06-14 20:57:18 +00003020** not invalidate a prior pointer, though of course the content of the buffer
3021** that the prior pointer points to will have been modified. Other kinds
mihailim1c492652008-06-21 18:02:16 +00003022** of conversion are done in place when it is possible, but sometimes they
3023** are not possible and in those cases prior pointers are invalidated.
drh6ed48bf2007-06-14 20:57:18 +00003024**
drhd68eee02009-12-11 03:44:18 +00003025** ^(The safest and easiest to remember policy is to invoke these routines
drh6ed48bf2007-06-14 20:57:18 +00003026** in one of the following ways:
3027**
mihailim1c492652008-06-21 18:02:16 +00003028** <ul>
drh6ed48bf2007-06-14 20:57:18 +00003029** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3030** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3031** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
drhd68eee02009-12-11 03:44:18 +00003032** </ul>)^
drh6ed48bf2007-06-14 20:57:18 +00003033**
mihailim1c492652008-06-21 18:02:16 +00003034** In other words, you should call sqlite3_column_text(),
3035** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3036** into the desired format, then invoke sqlite3_column_bytes() or
3037** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
3038** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3039** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3040** with calls to sqlite3_column_bytes().
drh32bc3f62007-08-21 20:25:39 +00003041**
drhd68eee02009-12-11 03:44:18 +00003042** ^The pointers returned are valid until a type conversion occurs as
drh32bc3f62007-08-21 20:25:39 +00003043** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
drhd68eee02009-12-11 03:44:18 +00003044** [sqlite3_finalize()] is called. ^The memory space used to hold strings
mihailim04bcc002008-06-22 10:21:27 +00003045** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
mihailim1c492652008-06-21 18:02:16 +00003046** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
drh32bc3f62007-08-21 20:25:39 +00003047** [sqlite3_free()].
drh4a50aac2007-08-23 02:47:53 +00003048**
drhd68eee02009-12-11 03:44:18 +00003049** ^(If a memory allocation error occurs during the evaluation of any
drh4a50aac2007-08-23 02:47:53 +00003050** of these routines, a default value is returned. The default value
3051** is either the integer 0, the floating point number 0.0, or a NULL
3052** pointer. Subsequent calls to [sqlite3_errcode()] will return
drhd68eee02009-12-11 03:44:18 +00003053** [SQLITE_NOMEM].)^
danielk1977106bb232004-05-21 10:08:53 +00003054*/
drhf4479502004-05-27 03:12:53 +00003055const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3056int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
3057int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
3058double sqlite3_column_double(sqlite3_stmt*, int iCol);
3059int sqlite3_column_int(sqlite3_stmt*, int iCol);
drh6d2069d2007-08-14 01:58:53 +00003060sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
drhf4479502004-05-27 03:12:53 +00003061const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3062const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
drh4f26d6c2004-05-26 23:25:30 +00003063int sqlite3_column_type(sqlite3_stmt*, int iCol);
drh4be8b512006-06-13 23:51:34 +00003064sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
danielk19774adee202004-05-08 08:23:19 +00003065
danielk197765904932004-05-26 06:18:37 +00003066/*
drhd68eee02009-12-11 03:44:18 +00003067** CAPI3REF: Destroy A Prepared Statement Object
drh6ed48bf2007-06-14 20:57:18 +00003068**
drhd68eee02009-12-11 03:44:18 +00003069** ^The sqlite3_finalize() function is called to delete a [prepared statement].
3070** ^If the statement was executed successfully or not executed at all, then
3071** SQLITE_OK is returned. ^If execution of the statement failed then an
mihailimebe796c2008-06-21 20:11:17 +00003072** [error code] or [extended error code] is returned.
danielk197765904932004-05-26 06:18:37 +00003073**
drhd68eee02009-12-11 03:44:18 +00003074** ^This routine can be called at any point during the execution of the
3075** [prepared statement]. ^If the virtual machine has not
drh6ed48bf2007-06-14 20:57:18 +00003076** completed execution when this routine is called, that is like
mihailimebe796c2008-06-21 20:11:17 +00003077** encountering an error or an [sqlite3_interrupt | interrupt].
drhd68eee02009-12-11 03:44:18 +00003078** ^Incomplete updates may be rolled back and transactions canceled,
mihailimebe796c2008-06-21 20:11:17 +00003079** depending on the circumstances, and the
drh33c1be32008-01-30 16:16:14 +00003080** [error code] returned will be [SQLITE_ABORT].
danielk197765904932004-05-26 06:18:37 +00003081*/
3082int sqlite3_finalize(sqlite3_stmt *pStmt);
3083
3084/*
drhd68eee02009-12-11 03:44:18 +00003085** CAPI3REF: Reset A Prepared Statement Object
drh6ed48bf2007-06-14 20:57:18 +00003086**
mihailimebe796c2008-06-21 20:11:17 +00003087** The sqlite3_reset() function is called to reset a [prepared statement]
3088** object back to its initial state, ready to be re-executed.
drhd68eee02009-12-11 03:44:18 +00003089** ^Any SQL statement variables that had values bound to them using
drh6ed48bf2007-06-14 20:57:18 +00003090** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3091** Use [sqlite3_clear_bindings()] to reset the bindings.
drh33c1be32008-01-30 16:16:14 +00003092**
drhd68eee02009-12-11 03:44:18 +00003093** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3094** back to the beginning of its program.
drh33c1be32008-01-30 16:16:14 +00003095**
drhd68eee02009-12-11 03:44:18 +00003096** ^If the most recent call to [sqlite3_step(S)] for the
3097** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3098** or if [sqlite3_step(S)] has never before been called on S,
3099** then [sqlite3_reset(S)] returns [SQLITE_OK].
drh33c1be32008-01-30 16:16:14 +00003100**
drhd68eee02009-12-11 03:44:18 +00003101** ^If the most recent call to [sqlite3_step(S)] for the
3102** [prepared statement] S indicated an error, then
3103** [sqlite3_reset(S)] returns an appropriate [error code].
drh33c1be32008-01-30 16:16:14 +00003104**
drhd68eee02009-12-11 03:44:18 +00003105** ^The [sqlite3_reset(S)] interface does not change the values
3106** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
danielk197765904932004-05-26 06:18:37 +00003107*/
3108int sqlite3_reset(sqlite3_stmt *pStmt);
3109
3110/*
drhd68eee02009-12-11 03:44:18 +00003111** CAPI3REF: Create Or Redefine SQL Functions
mihailimefc8e8a2008-06-21 16:47:09 +00003112** KEYWORDS: {function creation routines}
3113** KEYWORDS: {application-defined SQL function}
3114** KEYWORDS: {application-defined SQL functions}
drh6ed48bf2007-06-14 20:57:18 +00003115**
drhd68eee02009-12-11 03:44:18 +00003116** ^These two functions (collectively known as "function creation routines")
mihailimebe796c2008-06-21 20:11:17 +00003117** are used to add SQL functions or aggregates or to redefine the behavior
3118** of existing SQL functions or aggregates. The only difference between the
3119** two is that the second parameter, the name of the (scalar) function or
3120** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16
3121** for sqlite3_create_function16().
danielk197765904932004-05-26 06:18:37 +00003122**
drh1c3cfc62008-03-08 12:37:30 +00003123** The first parameter is the [database connection] to which the SQL
drhd68eee02009-12-11 03:44:18 +00003124** function is to be added. ^If a single program uses more than one database
mihailimebe796c2008-06-21 20:11:17 +00003125** connection internally, then SQL functions must be added individually to
3126** each database connection.
danielk197765904932004-05-26 06:18:37 +00003127**
mihailimebe796c2008-06-21 20:11:17 +00003128** The second parameter is the name of the SQL function to be created or
drhd68eee02009-12-11 03:44:18 +00003129** redefined. ^The length of the name is limited to 255 bytes, exclusive of
mihailimebe796c2008-06-21 20:11:17 +00003130** the zero-terminator. Note that the name length limit is in bytes, not
drhd68eee02009-12-11 03:44:18 +00003131** characters. ^Any attempt to create a function with a longer name
mihailimebe796c2008-06-21 20:11:17 +00003132** will result in [SQLITE_ERROR] being returned.
drh6ed48bf2007-06-14 20:57:18 +00003133**
drhd68eee02009-12-11 03:44:18 +00003134** ^The third parameter (nArg)
drhc8075422008-09-10 13:09:23 +00003135** is the number of arguments that the SQL function or
drhd68eee02009-12-11 03:44:18 +00003136** aggregate takes. ^If this parameter is -1, then the SQL function or
drh97602f82009-05-24 11:07:49 +00003137** aggregate may take any number of arguments between 0 and the limit
3138** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
drh09943b52009-05-24 21:59:27 +00003139** parameter is less than -1 or greater than 127 then the behavior is
3140** undefined.
danielk197765904932004-05-26 06:18:37 +00003141**
mihailimebe796c2008-06-21 20:11:17 +00003142** The fourth parameter, eTextRep, specifies what
drh6ed48bf2007-06-14 20:57:18 +00003143** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3144** its parameters. Any SQL function implementation should be able to work
3145** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
drhd68eee02009-12-11 03:44:18 +00003146** more efficient with one encoding than another. ^An application may
drh6d2069d2007-08-14 01:58:53 +00003147** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
drh6ed48bf2007-06-14 20:57:18 +00003148** times with the same function but with different values of eTextRep.
drhd68eee02009-12-11 03:44:18 +00003149** ^When multiple implementations of the same function are available, SQLite
drh6ed48bf2007-06-14 20:57:18 +00003150** will pick the one that involves the least amount of data conversion.
mihailimebe796c2008-06-21 20:11:17 +00003151** If there is only a single implementation which does not care what text
3152** encoding is used, then the fourth argument should be [SQLITE_ANY].
drh6ed48bf2007-06-14 20:57:18 +00003153**
drhd68eee02009-12-11 03:44:18 +00003154** ^(The fifth parameter is an arbitrary pointer. The implementation of the
3155** function can gain access to this pointer using [sqlite3_user_data()].)^
danielk1977d02eb1f2004-06-06 09:44:03 +00003156**
danielk197765904932004-05-26 06:18:37 +00003157** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
mihailimebe796c2008-06-21 20:11:17 +00003158** pointers to C-language functions that implement the SQL function or
drhd68eee02009-12-11 03:44:18 +00003159** aggregate. ^A scalar SQL function requires an implementation of the xFunc
3160** callback only; NULL pointers should be passed as the xStep and xFinal
3161** parameters. ^An aggregate SQL function requires an implementation of xStep
3162** and xFinal and NULL should be passed for xFunc. ^To delete an existing
mihailimebe796c2008-06-21 20:11:17 +00003163** SQL function or aggregate, pass NULL for all three function callbacks.
drh6ed48bf2007-06-14 20:57:18 +00003164**
drhd68eee02009-12-11 03:44:18 +00003165** ^It is permitted to register multiple implementations of the same
drh6ed48bf2007-06-14 20:57:18 +00003166** functions with the same name but with either differing numbers of
drhd68eee02009-12-11 03:44:18 +00003167** arguments or differing preferred text encodings. ^SQLite will use
drh6aa5f152009-08-19 15:57:07 +00003168** the implementation that most closely matches the way in which the
drhd68eee02009-12-11 03:44:18 +00003169** SQL function is used. ^A function implementation with a non-negative
drhc8075422008-09-10 13:09:23 +00003170** nArg parameter is a better match than a function implementation with
drhd68eee02009-12-11 03:44:18 +00003171** a negative nArg. ^A function where the preferred text encoding
drhc8075422008-09-10 13:09:23 +00003172** matches the database encoding is a better
3173** match than a function where the encoding is different.
drhd68eee02009-12-11 03:44:18 +00003174** ^A function where the encoding difference is between UTF16le and UTF16be
drhc8075422008-09-10 13:09:23 +00003175** is a closer match than a function where the encoding difference is
3176** between UTF8 and UTF16.
3177**
drhd68eee02009-12-11 03:44:18 +00003178** ^Built-in functions may be overloaded by new application-defined functions.
3179** ^The first application-defined function with a given name overrides all
drhc8075422008-09-10 13:09:23 +00003180** built-in functions in the same [database connection] with the same name.
drhd68eee02009-12-11 03:44:18 +00003181** ^Subsequent application-defined functions of the same name only override
drhc8075422008-09-10 13:09:23 +00003182** prior application-defined functions that are an exact match for the
3183** number of parameters and preferred encoding.
3184**
drhd68eee02009-12-11 03:44:18 +00003185** ^An application-defined function is permitted to call other
drhc8075422008-09-10 13:09:23 +00003186** SQLite interfaces. However, such calls must not
3187** close the database connection nor finalize or reset the prepared
3188** statement in which the function is running.
danielk197765904932004-05-26 06:18:37 +00003189*/
3190int sqlite3_create_function(
drh33c1be32008-01-30 16:16:14 +00003191 sqlite3 *db,
danielk197765904932004-05-26 06:18:37 +00003192 const char *zFunctionName,
3193 int nArg,
3194 int eTextRep,
drh33c1be32008-01-30 16:16:14 +00003195 void *pApp,
danielk197765904932004-05-26 06:18:37 +00003196 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3197 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3198 void (*xFinal)(sqlite3_context*)
3199);
3200int sqlite3_create_function16(
drh33c1be32008-01-30 16:16:14 +00003201 sqlite3 *db,
danielk197765904932004-05-26 06:18:37 +00003202 const void *zFunctionName,
3203 int nArg,
3204 int eTextRep,
drh33c1be32008-01-30 16:16:14 +00003205 void *pApp,
danielk197765904932004-05-26 06:18:37 +00003206 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3207 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3208 void (*xFinal)(sqlite3_context*)
3209);
3210
3211/*
drhd68eee02009-12-11 03:44:18 +00003212** CAPI3REF: Text Encodings
drh6ed48bf2007-06-14 20:57:18 +00003213**
3214** These constant define integer codes that represent the various
3215** text encodings supported by SQLite.
danielk197765904932004-05-26 06:18:37 +00003216*/
drh6ed48bf2007-06-14 20:57:18 +00003217#define SQLITE_UTF8 1
3218#define SQLITE_UTF16LE 2
3219#define SQLITE_UTF16BE 3
3220#define SQLITE_UTF16 4 /* Use native byte order */
3221#define SQLITE_ANY 5 /* sqlite3_create_function only */
3222#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
danielk197765904932004-05-26 06:18:37 +00003223
danielk19770ffba6b2004-05-24 09:10:10 +00003224/*
drhd5a68d32008-08-04 13:44:57 +00003225** CAPI3REF: Deprecated Functions
3226** DEPRECATED
drh6ed48bf2007-06-14 20:57:18 +00003227**
drhd5a68d32008-08-04 13:44:57 +00003228** These functions are [deprecated]. In order to maintain
3229** backwards compatibility with older code, these functions continue
3230** to be supported. However, new applications should avoid
drh6ed48bf2007-06-14 20:57:18 +00003231** the use of these functions. To help encourage people to avoid
shane7ba429a2008-11-10 17:08:49 +00003232** using these functions, we are not going to tell you what they do.
drh6ed48bf2007-06-14 20:57:18 +00003233*/
shaneeec556d2008-10-12 00:27:53 +00003234#ifndef SQLITE_OMIT_DEPRECATED
shanea79c3cc2008-08-11 17:27:01 +00003235SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
3236SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
3237SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
3238SQLITE_DEPRECATED int sqlite3_global_recover(void);
3239SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
3240SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
shaneeec556d2008-10-12 00:27:53 +00003241#endif
drh6ed48bf2007-06-14 20:57:18 +00003242
3243/*
drhd68eee02009-12-11 03:44:18 +00003244** CAPI3REF: Obtaining SQL Function Parameter Values
drh6ed48bf2007-06-14 20:57:18 +00003245**
3246** The C-language implementation of SQL functions and aggregates uses
3247** this set of interface routines to access the parameter values on
3248** the function or aggregate.
3249**
3250** The xFunc (for scalar functions) or xStep (for aggregates) parameters
3251** to [sqlite3_create_function()] and [sqlite3_create_function16()]
3252** define callbacks that implement the SQL functions and aggregates.
3253** The 4th parameter to these callbacks is an array of pointers to
drhaa28e142008-03-18 13:47:20 +00003254** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
drh6ed48bf2007-06-14 20:57:18 +00003255** each parameter to the SQL function. These routines are used to
3256** extract values from the [sqlite3_value] objects.
3257**
drhaa28e142008-03-18 13:47:20 +00003258** These routines work only with [protected sqlite3_value] objects.
3259** Any attempt to use these routines on an [unprotected sqlite3_value]
3260** object results in undefined behavior.
3261**
drhd68eee02009-12-11 03:44:18 +00003262** ^These routines work just like the corresponding [column access functions]
mihailim1c492652008-06-21 18:02:16 +00003263** except that these routines take a single [protected sqlite3_value] object
3264** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
drh6ed48bf2007-06-14 20:57:18 +00003265**
drhd68eee02009-12-11 03:44:18 +00003266** ^The sqlite3_value_text16() interface extracts a UTF-16 string
3267** in the native byte-order of the host machine. ^The
drh6ed48bf2007-06-14 20:57:18 +00003268** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
mihailimebe796c2008-06-21 20:11:17 +00003269** extract UTF-16 strings as big-endian and little-endian respectively.
drh6ed48bf2007-06-14 20:57:18 +00003270**
drhd68eee02009-12-11 03:44:18 +00003271** ^(The sqlite3_value_numeric_type() interface attempts to apply
drh6ed48bf2007-06-14 20:57:18 +00003272** numeric affinity to the value. This means that an attempt is
3273** made to convert the value to an integer or floating point. If
drhf5befa02007-12-06 02:42:07 +00003274** such a conversion is possible without loss of information (in other
mihailimebe796c2008-06-21 20:11:17 +00003275** words, if the value is a string that looks like a number)
3276** then the conversion is performed. Otherwise no conversion occurs.
drhd68eee02009-12-11 03:44:18 +00003277** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
drh6ed48bf2007-06-14 20:57:18 +00003278**
mihailimebe796c2008-06-21 20:11:17 +00003279** Please pay particular attention to the fact that the pointer returned
3280** from [sqlite3_value_blob()], [sqlite3_value_text()], or
drh6ed48bf2007-06-14 20:57:18 +00003281** [sqlite3_value_text16()] can be invalidated by a subsequent call to
drh6d2069d2007-08-14 01:58:53 +00003282** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
mihailimebe796c2008-06-21 20:11:17 +00003283** or [sqlite3_value_text16()].
drhe53831d2007-08-17 01:14:38 +00003284**
3285** These routines must be called from the same thread as
drhaa28e142008-03-18 13:47:20 +00003286** the SQL function that supplied the [sqlite3_value*] parameters.
danielk19770ffba6b2004-05-24 09:10:10 +00003287*/
drhf4479502004-05-27 03:12:53 +00003288const void *sqlite3_value_blob(sqlite3_value*);
3289int sqlite3_value_bytes(sqlite3_value*);
3290int sqlite3_value_bytes16(sqlite3_value*);
3291double sqlite3_value_double(sqlite3_value*);
3292int sqlite3_value_int(sqlite3_value*);
drh6d2069d2007-08-14 01:58:53 +00003293sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
drhf4479502004-05-27 03:12:53 +00003294const unsigned char *sqlite3_value_text(sqlite3_value*);
3295const void *sqlite3_value_text16(sqlite3_value*);
danielk1977d8123362004-06-12 09:25:12 +00003296const void *sqlite3_value_text16le(sqlite3_value*);
3297const void *sqlite3_value_text16be(sqlite3_value*);
danielk197793d46752004-05-23 13:30:58 +00003298int sqlite3_value_type(sqlite3_value*);
drh29d72102006-02-09 22:13:41 +00003299int sqlite3_value_numeric_type(sqlite3_value*);
danielk19770ffba6b2004-05-24 09:10:10 +00003300
3301/*
drhd68eee02009-12-11 03:44:18 +00003302** CAPI3REF: Obtain Aggregate Function Context
drh6ed48bf2007-06-14 20:57:18 +00003303**
drhd68eee02009-12-11 03:44:18 +00003304** Implementions of aggregate SQL functions use this
3305** routine to allocate memory for storing their state.
mihailimebe796c2008-06-21 20:11:17 +00003306**
drhd68eee02009-12-11 03:44:18 +00003307** ^The first time the sqlite3_aggregate_context(C,N) routine is called
3308** for a particular aggregate function, SQLite
3309** allocates N of memory, zeroes out that memory, and returns a pointer
3310** to the new memory. ^On second and subsequent calls to
3311** sqlite3_aggregate_context() for the same aggregate function instance,
3312** the same buffer is returned. Sqlite3_aggregate_context() is normally
3313** called once for each invocation of the xStep callback and then one
3314** last time when the xFinal callback is invoked. ^(When no rows match
3315** an aggregate query, the xStep() callback of the aggregate function
3316** implementation is never called and xFinal() is called exactly once.
3317** In those cases, sqlite3_aggregate_context() might be called for the
3318** first time from within xFinal().)^
danielk19770ae8b832004-05-25 12:05:56 +00003319**
drhd68eee02009-12-11 03:44:18 +00003320** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
3321** less than or equal to zero or if a memory allocate error occurs.
drh6ed48bf2007-06-14 20:57:18 +00003322**
drhd68eee02009-12-11 03:44:18 +00003323** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
3324** determined by the N parameter on first successful call. Changing the
3325** value of N in subsequent call to sqlite3_aggregate_context() within
3326** the same aggregate function instance will not resize the memory
3327** allocation.)^
3328**
3329** ^SQLite automatically frees the memory allocated by
3330** sqlite3_aggregate_context() when the aggregate query concludes.
3331**
3332** The first parameter must be a copy of the
mihailimebe796c2008-06-21 20:11:17 +00003333** [sqlite3_context | SQL function context] that is the first parameter
drhd68eee02009-12-11 03:44:18 +00003334** to the xStep or xFinal callback routine that implements the aggregate
3335** function.
drhe53831d2007-08-17 01:14:38 +00003336**
3337** This routine must be called from the same thread in which
drh605264d2007-08-21 15:13:19 +00003338** the aggregate SQL function is running.
danielk19770ae8b832004-05-25 12:05:56 +00003339*/
drh4f26d6c2004-05-26 23:25:30 +00003340void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
danielk19777e18c252004-05-25 11:47:24 +00003341
3342/*
drhd68eee02009-12-11 03:44:18 +00003343** CAPI3REF: User Data For Functions
drh6ed48bf2007-06-14 20:57:18 +00003344**
drhd68eee02009-12-11 03:44:18 +00003345** ^The sqlite3_user_data() interface returns a copy of
drhf5befa02007-12-06 02:42:07 +00003346** the pointer that was the pUserData parameter (the 5th parameter)
shane26b34032008-05-23 17:21:09 +00003347** of the [sqlite3_create_function()]
drhf5befa02007-12-06 02:42:07 +00003348** and [sqlite3_create_function16()] routines that originally
drhfa4a4b92008-03-19 21:45:51 +00003349** registered the application defined function.
3350**
drhd68eee02009-12-11 03:44:18 +00003351** This routine must be called from the same thread in which
3352** the application-defined function is running.
3353*/
3354void *sqlite3_user_data(sqlite3_context*);
3355
3356/*
3357** CAPI3REF: Database Connection For Functions
3358**
3359** ^The sqlite3_context_db_handle() interface returns a copy of
3360** the pointer to the [database connection] (the 1st parameter)
3361** of the [sqlite3_create_function()]
3362** and [sqlite3_create_function16()] routines that originally
3363** registered the application defined function.
drhfa4a4b92008-03-19 21:45:51 +00003364*/
3365sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
3366
3367/*
drhd68eee02009-12-11 03:44:18 +00003368** CAPI3REF: Function Auxiliary Data
drh6ed48bf2007-06-14 20:57:18 +00003369**
3370** The following two functions may be used by scalar SQL functions to
mihailimebe796c2008-06-21 20:11:17 +00003371** associate metadata with argument values. If the same value is passed to
drh6ed48bf2007-06-14 20:57:18 +00003372** multiple invocations of the same SQL function during query execution, under
mihailimebe796c2008-06-21 20:11:17 +00003373** some circumstances the associated metadata may be preserved. This may
danielk1977682f68b2004-06-05 10:22:17 +00003374** be used, for example, to add a regular-expression matching scalar
3375** function. The compiled version of the regular expression is stored as
mihailimebe796c2008-06-21 20:11:17 +00003376** metadata associated with the SQL value passed as the regular expression
drh6ed48bf2007-06-14 20:57:18 +00003377** pattern. The compiled regular expression can be reused on multiple
3378** invocations of the same function so that the original pattern string
3379** does not need to be recompiled on each invocation.
danielk1977682f68b2004-06-05 10:22:17 +00003380**
drhd68eee02009-12-11 03:44:18 +00003381** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
drhf5befa02007-12-06 02:42:07 +00003382** associated by the sqlite3_set_auxdata() function with the Nth argument
drhd68eee02009-12-11 03:44:18 +00003383** value to the application-defined function. ^If no metadata has been ever
mihailimebe796c2008-06-21 20:11:17 +00003384** been set for the Nth argument of the function, or if the corresponding
3385** function parameter has changed since the meta-data was set,
3386** then sqlite3_get_auxdata() returns a NULL pointer.
danielk1977682f68b2004-06-05 10:22:17 +00003387**
drhd68eee02009-12-11 03:44:18 +00003388** ^The sqlite3_set_auxdata() interface saves the metadata
mihailimebe796c2008-06-21 20:11:17 +00003389** pointed to by its 3rd parameter as the metadata for the N-th
drhafc91042008-02-21 02:09:45 +00003390** argument of the application-defined function. Subsequent
drhf5befa02007-12-06 02:42:07 +00003391** calls to sqlite3_get_auxdata() might return this data, if it has
mihailimebe796c2008-06-21 20:11:17 +00003392** not been destroyed.
drhd68eee02009-12-11 03:44:18 +00003393** ^If it is not NULL, SQLite will invoke the destructor
drhf5befa02007-12-06 02:42:07 +00003394** function given by the 4th parameter to sqlite3_set_auxdata() on
mihailimebe796c2008-06-21 20:11:17 +00003395** the metadata when the corresponding function parameter changes
drhafc91042008-02-21 02:09:45 +00003396** or when the SQL statement completes, whichever comes first.
3397**
mihailimebe796c2008-06-21 20:11:17 +00003398** SQLite is free to call the destructor and drop metadata on any
drhd68eee02009-12-11 03:44:18 +00003399** parameter of any function at any time. ^The only guarantee is that
mihailimebe796c2008-06-21 20:11:17 +00003400** the destructor will be called before the metadata is dropped.
danielk1977682f68b2004-06-05 10:22:17 +00003401**
drhd68eee02009-12-11 03:44:18 +00003402** ^(In practice, metadata is preserved between function calls for
danielk1977682f68b2004-06-05 10:22:17 +00003403** expressions that are constant at compile time. This includes literal
drhd68eee02009-12-11 03:44:18 +00003404** values and [parameters].)^
drhe53831d2007-08-17 01:14:38 +00003405**
drhb21c8cd2007-08-21 19:33:56 +00003406** These routines must be called from the same thread in which
3407** the SQL function is running.
danielk1977682f68b2004-06-05 10:22:17 +00003408*/
drhf5befa02007-12-06 02:42:07 +00003409void *sqlite3_get_auxdata(sqlite3_context*, int N);
3410void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
danielk1977682f68b2004-06-05 10:22:17 +00003411
drha2854222004-06-17 19:04:17 +00003412
3413/*
drhd68eee02009-12-11 03:44:18 +00003414** CAPI3REF: Constants Defining Special Destructor Behavior
drh6ed48bf2007-06-14 20:57:18 +00003415**
mihailimebe796c2008-06-21 20:11:17 +00003416** These are special values for the destructor that is passed in as the
drhd68eee02009-12-11 03:44:18 +00003417** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
drha2854222004-06-17 19:04:17 +00003418** argument is SQLITE_STATIC, it means that the content pointer is constant
drhd68eee02009-12-11 03:44:18 +00003419** and will never change. It does not need to be destroyed. ^The
drha2854222004-06-17 19:04:17 +00003420** SQLITE_TRANSIENT value means that the content will likely change in
3421** the near future and that SQLite should make its own private copy of
3422** the content before returning.
drh6c9121a2007-01-26 00:51:43 +00003423**
3424** The typedef is necessary to work around problems in certain
3425** C++ compilers. See ticket #2191.
drha2854222004-06-17 19:04:17 +00003426*/
drh6c9121a2007-01-26 00:51:43 +00003427typedef void (*sqlite3_destructor_type)(void*);
3428#define SQLITE_STATIC ((sqlite3_destructor_type)0)
3429#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
danielk1977d8123362004-06-12 09:25:12 +00003430
danielk1977682f68b2004-06-05 10:22:17 +00003431/*
drhd68eee02009-12-11 03:44:18 +00003432** CAPI3REF: Setting The Result Of An SQL Function
drh6ed48bf2007-06-14 20:57:18 +00003433**
3434** These routines are used by the xFunc or xFinal callbacks that
3435** implement SQL functions and aggregates. See
3436** [sqlite3_create_function()] and [sqlite3_create_function16()]
3437** for additional information.
3438**
mihailimebe796c2008-06-21 20:11:17 +00003439** These functions work very much like the [parameter binding] family of
3440** functions used to bind values to host parameters in prepared statements.
3441** Refer to the [SQL parameter] documentation for additional information.
drh6ed48bf2007-06-14 20:57:18 +00003442**
drhd68eee02009-12-11 03:44:18 +00003443** ^The sqlite3_result_blob() interface sets the result from
mihailimebe796c2008-06-21 20:11:17 +00003444** an application-defined function to be the BLOB whose content is pointed
drhf5befa02007-12-06 02:42:07 +00003445** to by the second parameter and which is N bytes long where N is the
mihailimebe796c2008-06-21 20:11:17 +00003446** third parameter.
3447**
drhd68eee02009-12-11 03:44:18 +00003448** ^The sqlite3_result_zeroblob() interfaces set the result of
mihailimebe796c2008-06-21 20:11:17 +00003449** the application-defined function to be a BLOB containing all zero
drhf5befa02007-12-06 02:42:07 +00003450** bytes and N bytes in size, where N is the value of the 2nd parameter.
drh6ed48bf2007-06-14 20:57:18 +00003451**
drhd68eee02009-12-11 03:44:18 +00003452** ^The sqlite3_result_double() interface sets the result from
mihailimebe796c2008-06-21 20:11:17 +00003453** an application-defined function to be a floating point value specified
drhf5befa02007-12-06 02:42:07 +00003454** by its 2nd argument.
drhe53831d2007-08-17 01:14:38 +00003455**
drhd68eee02009-12-11 03:44:18 +00003456** ^The sqlite3_result_error() and sqlite3_result_error16() functions
drhf5befa02007-12-06 02:42:07 +00003457** cause the implemented SQL function to throw an exception.
drhd68eee02009-12-11 03:44:18 +00003458** ^SQLite uses the string pointed to by the
drhf5befa02007-12-06 02:42:07 +00003459** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
drhd68eee02009-12-11 03:44:18 +00003460** as the text of an error message. ^SQLite interprets the error
3461** message string from sqlite3_result_error() as UTF-8. ^SQLite
mihailimebe796c2008-06-21 20:11:17 +00003462** interprets the string from sqlite3_result_error16() as UTF-16 in native
drhd68eee02009-12-11 03:44:18 +00003463** byte order. ^If the third parameter to sqlite3_result_error()
drhf5befa02007-12-06 02:42:07 +00003464** or sqlite3_result_error16() is negative then SQLite takes as the error
3465** message all text up through the first zero character.
drhd68eee02009-12-11 03:44:18 +00003466** ^If the third parameter to sqlite3_result_error() or
drhf5befa02007-12-06 02:42:07 +00003467** sqlite3_result_error16() is non-negative then SQLite takes that many
3468** bytes (not characters) from the 2nd parameter as the error message.
drhd68eee02009-12-11 03:44:18 +00003469** ^The sqlite3_result_error() and sqlite3_result_error16()
mihailimebe796c2008-06-21 20:11:17 +00003470** routines make a private copy of the error message text before
drhafc91042008-02-21 02:09:45 +00003471** they return. Hence, the calling function can deallocate or
drhf5befa02007-12-06 02:42:07 +00003472** modify the text after they return without harm.
drhd68eee02009-12-11 03:44:18 +00003473** ^The sqlite3_result_error_code() function changes the error code
3474** returned by SQLite as a result of an error in a function. ^By default,
3475** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
drh00e087b2008-04-10 17:14:07 +00003476** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
drhf5befa02007-12-06 02:42:07 +00003477**
drhd68eee02009-12-11 03:44:18 +00003478** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
mihailimebe796c2008-06-21 20:11:17 +00003479** indicating that a string or BLOB is to long to represent.
3480**
drhd68eee02009-12-11 03:44:18 +00003481** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
mihailimebe796c2008-06-21 20:11:17 +00003482** indicating that a memory allocation failed.
drhf5befa02007-12-06 02:42:07 +00003483**
drhd68eee02009-12-11 03:44:18 +00003484** ^The sqlite3_result_int() interface sets the return value
drhf5befa02007-12-06 02:42:07 +00003485** of the application-defined function to be the 32-bit signed integer
3486** value given in the 2nd argument.
drhd68eee02009-12-11 03:44:18 +00003487** ^The sqlite3_result_int64() interface sets the return value
drhf5befa02007-12-06 02:42:07 +00003488** of the application-defined function to be the 64-bit signed integer
3489** value given in the 2nd argument.
3490**
drhd68eee02009-12-11 03:44:18 +00003491** ^The sqlite3_result_null() interface sets the return value
drhf5befa02007-12-06 02:42:07 +00003492** of the application-defined function to be NULL.
3493**
drhd68eee02009-12-11 03:44:18 +00003494** ^The sqlite3_result_text(), sqlite3_result_text16(),
drhf5befa02007-12-06 02:42:07 +00003495** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
3496** set the return value of the application-defined function to be
3497** a text string which is represented as UTF-8, UTF-16 native byte order,
3498** UTF-16 little endian, or UTF-16 big endian, respectively.
drhd68eee02009-12-11 03:44:18 +00003499** ^SQLite takes the text result from the application from
drhf5befa02007-12-06 02:42:07 +00003500** the 2nd parameter of the sqlite3_result_text* interfaces.
drhd68eee02009-12-11 03:44:18 +00003501** ^If the 3rd parameter to the sqlite3_result_text* interfaces
mihailimebe796c2008-06-21 20:11:17 +00003502** is negative, then SQLite takes result text from the 2nd parameter
drhf5befa02007-12-06 02:42:07 +00003503** through the first zero character.
drhd68eee02009-12-11 03:44:18 +00003504** ^If the 3rd parameter to the sqlite3_result_text* interfaces
drhf5befa02007-12-06 02:42:07 +00003505** is non-negative, then as many bytes (not characters) of the text
3506** pointed to by the 2nd parameter are taken as the application-defined
3507** function result.
drhd68eee02009-12-11 03:44:18 +00003508** ^If the 4th parameter to the sqlite3_result_text* interfaces
drhf5befa02007-12-06 02:42:07 +00003509** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
mihailimebe796c2008-06-21 20:11:17 +00003510** function as the destructor on the text or BLOB result when it has
drhf5befa02007-12-06 02:42:07 +00003511** finished using that result.
drhd68eee02009-12-11 03:44:18 +00003512** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
mihailimebe796c2008-06-21 20:11:17 +00003513** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
3514** assumes that the text or BLOB result is in constant space and does not
drh9e42f8a2009-08-13 20:15:29 +00003515** copy the content of the parameter nor call a destructor on the content
3516** when it has finished using that result.
drhd68eee02009-12-11 03:44:18 +00003517** ^If the 4th parameter to the sqlite3_result_text* interfaces
drhf5befa02007-12-06 02:42:07 +00003518** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
3519** then SQLite makes a copy of the result into space obtained from
3520** from [sqlite3_malloc()] before it returns.
3521**
drhd68eee02009-12-11 03:44:18 +00003522** ^The sqlite3_result_value() interface sets the result of
drhaa28e142008-03-18 13:47:20 +00003523** the application-defined function to be a copy the
drhd68eee02009-12-11 03:44:18 +00003524** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
drhf5befa02007-12-06 02:42:07 +00003525** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
mihailimebe796c2008-06-21 20:11:17 +00003526** so that the [sqlite3_value] specified in the parameter may change or
drhf5befa02007-12-06 02:42:07 +00003527** be deallocated after sqlite3_result_value() returns without harm.
drhd68eee02009-12-11 03:44:18 +00003528** ^A [protected sqlite3_value] object may always be used where an
drhaa28e142008-03-18 13:47:20 +00003529** [unprotected sqlite3_value] object is required, so either
3530** kind of [sqlite3_value] object can be used with this interface.
drhf5befa02007-12-06 02:42:07 +00003531**
mihailimebe796c2008-06-21 20:11:17 +00003532** If these routines are called from within the different thread
shane26b34032008-05-23 17:21:09 +00003533** than the one containing the application-defined function that received
drhf5befa02007-12-06 02:42:07 +00003534** the [sqlite3_context] pointer, the results are undefined.
danielk19777e18c252004-05-25 11:47:24 +00003535*/
danielk1977d8123362004-06-12 09:25:12 +00003536void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
drh4f26d6c2004-05-26 23:25:30 +00003537void sqlite3_result_double(sqlite3_context*, double);
danielk19777e18c252004-05-25 11:47:24 +00003538void sqlite3_result_error(sqlite3_context*, const char*, int);
3539void sqlite3_result_error16(sqlite3_context*, const void*, int);
drh6ed48bf2007-06-14 20:57:18 +00003540void sqlite3_result_error_toobig(sqlite3_context*);
danielk1977a1644fd2007-08-29 12:31:25 +00003541void sqlite3_result_error_nomem(sqlite3_context*);
drh69544ec2008-02-06 14:11:34 +00003542void sqlite3_result_error_code(sqlite3_context*, int);
drh4f26d6c2004-05-26 23:25:30 +00003543void sqlite3_result_int(sqlite3_context*, int);
drh6d2069d2007-08-14 01:58:53 +00003544void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
drh4f26d6c2004-05-26 23:25:30 +00003545void sqlite3_result_null(sqlite3_context*);
danielk1977d8123362004-06-12 09:25:12 +00003546void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
3547void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
3548void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
3549void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
drh4f26d6c2004-05-26 23:25:30 +00003550void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
drhb026e052007-05-02 01:34:31 +00003551void sqlite3_result_zeroblob(sqlite3_context*, int n);
drhf9b596e2004-05-26 16:54:42 +00003552
drh52619df2004-06-11 17:48:02 +00003553/*
drhd68eee02009-12-11 03:44:18 +00003554** CAPI3REF: Define New Collating Sequences
drh6ed48bf2007-06-14 20:57:18 +00003555**
3556** These functions are used to add new collation sequences to the
mihailimebe796c2008-06-21 20:11:17 +00003557** [database connection] specified as the first argument.
danielk19777cedc8d2004-06-10 10:50:08 +00003558**
drhd68eee02009-12-11 03:44:18 +00003559** ^The name of the new collation sequence is specified as a UTF-8 string
drh6ed48bf2007-06-14 20:57:18 +00003560** for sqlite3_create_collation() and sqlite3_create_collation_v2()
drhd68eee02009-12-11 03:44:18 +00003561** and a UTF-16 string for sqlite3_create_collation16(). ^In all cases
drh6ed48bf2007-06-14 20:57:18 +00003562** the name is passed as the second function argument.
danielk19777cedc8d2004-06-10 10:50:08 +00003563**
drhd68eee02009-12-11 03:44:18 +00003564** ^The third argument may be one of the constants [SQLITE_UTF8],
drh51c7d862009-04-27 18:46:06 +00003565** [SQLITE_UTF16LE], or [SQLITE_UTF16BE], indicating that the user-supplied
danielk19777cedc8d2004-06-10 10:50:08 +00003566** routine expects to be passed pointers to strings encoded using UTF-8,
drhd68eee02009-12-11 03:44:18 +00003567** UTF-16 little-endian, or UTF-16 big-endian, respectively. ^The
drh51c7d862009-04-27 18:46:06 +00003568** third argument might also be [SQLITE_UTF16] to indicate that the routine
3569** expects pointers to be UTF-16 strings in the native byte order, or the
3570** argument can be [SQLITE_UTF16_ALIGNED] if the
drh4145f832007-10-12 18:30:12 +00003571** the routine expects pointers to 16-bit word aligned strings
drh51c7d862009-04-27 18:46:06 +00003572** of UTF-16 in the native byte order.
danielk19777cedc8d2004-06-10 10:50:08 +00003573**
3574** A pointer to the user supplied routine must be passed as the fifth
drhd68eee02009-12-11 03:44:18 +00003575** argument. ^If it is NULL, this is the same as deleting the collation
drhf5befa02007-12-06 02:42:07 +00003576** sequence (so that SQLite cannot call it anymore).
drhd68eee02009-12-11 03:44:18 +00003577** ^Each time the application supplied function is invoked, it is passed
mihailimebe796c2008-06-21 20:11:17 +00003578** as its first parameter a copy of the void* passed as the fourth argument
3579** to sqlite3_create_collation() or sqlite3_create_collation16().
danielk19777cedc8d2004-06-10 10:50:08 +00003580**
drhd68eee02009-12-11 03:44:18 +00003581** ^The remaining arguments to the application-supplied routine are two strings,
drh33c1be32008-01-30 16:16:14 +00003582** each represented by a (length, data) pair and encoded in the encoding
danielk19777cedc8d2004-06-10 10:50:08 +00003583** that was passed as the third argument when the collation sequence was
mihailim04bcc002008-06-22 10:21:27 +00003584** registered. {END} The application defined collation routine should
mihailimebe796c2008-06-21 20:11:17 +00003585** return negative, zero or positive if the first string is less than,
3586** equal to, or greater than the second string. i.e. (STRING1 - STRING2).
drh6ed48bf2007-06-14 20:57:18 +00003587**
drhd68eee02009-12-11 03:44:18 +00003588** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
shane26b34032008-05-23 17:21:09 +00003589** except that it takes an extra argument which is a destructor for
drhd68eee02009-12-11 03:44:18 +00003590** the collation. ^The destructor is called when the collation is
drh6ed48bf2007-06-14 20:57:18 +00003591** destroyed and is passed a copy of the fourth parameter void* pointer
drhf5befa02007-12-06 02:42:07 +00003592** of the sqlite3_create_collation_v2().
drhd68eee02009-12-11 03:44:18 +00003593** ^Collations are destroyed when they are overridden by later calls to the
mihailimebe796c2008-06-21 20:11:17 +00003594** collation creation functions or when the [database connection] is closed
3595** using [sqlite3_close()].
drhafc91042008-02-21 02:09:45 +00003596**
drh51c7d862009-04-27 18:46:06 +00003597** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
danielk19777cedc8d2004-06-10 10:50:08 +00003598*/
danielk19770202b292004-06-09 09:55:16 +00003599int sqlite3_create_collation(
3600 sqlite3*,
3601 const char *zName,
danielk19777cedc8d2004-06-10 10:50:08 +00003602 int eTextRep,
danielk19770202b292004-06-09 09:55:16 +00003603 void*,
3604 int(*xCompare)(void*,int,const void*,int,const void*)
3605);
drh6ed48bf2007-06-14 20:57:18 +00003606int sqlite3_create_collation_v2(
3607 sqlite3*,
3608 const char *zName,
3609 int eTextRep,
3610 void*,
3611 int(*xCompare)(void*,int,const void*,int,const void*),
3612 void(*xDestroy)(void*)
3613);
danielk19770202b292004-06-09 09:55:16 +00003614int sqlite3_create_collation16(
3615 sqlite3*,
mihailimbda2e622008-06-23 11:23:14 +00003616 const void *zName,
danielk19777cedc8d2004-06-10 10:50:08 +00003617 int eTextRep,
danielk19770202b292004-06-09 09:55:16 +00003618 void*,
3619 int(*xCompare)(void*,int,const void*,int,const void*)
3620);
3621
danielk19777cedc8d2004-06-10 10:50:08 +00003622/*
drh9cd29642008-07-23 00:52:55 +00003623** CAPI3REF: Collation Needed Callbacks {H16700} <S20300>
danielk1977a393c032007-05-07 14:58:53 +00003624**
drhd68eee02009-12-11 03:44:18 +00003625** ^To avoid having to register all collation sequences before a database
danielk19777cedc8d2004-06-10 10:50:08 +00003626** can be used, a single callback function may be registered with the
mihailimdc884822008-06-22 08:58:50 +00003627** [database connection] to be called whenever an undefined collation
3628** sequence is required.
danielk19777cedc8d2004-06-10 10:50:08 +00003629**
drhd68eee02009-12-11 03:44:18 +00003630** ^If the function is registered using the sqlite3_collation_needed() API,
danielk19777cedc8d2004-06-10 10:50:08 +00003631** then it is passed the names of undefined collation sequences as strings
drhd68eee02009-12-11 03:44:18 +00003632** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
mihailimdc884822008-06-22 08:58:50 +00003633** the names are passed as UTF-16 in machine native byte order.
drhd68eee02009-12-11 03:44:18 +00003634** ^A call to either function replaces any existing callback.
danielk19777cedc8d2004-06-10 10:50:08 +00003635**
drhd68eee02009-12-11 03:44:18 +00003636** ^(When the callback is invoked, the first argument passed is a copy
danielk19777cedc8d2004-06-10 10:50:08 +00003637** of the second argument to sqlite3_collation_needed() or
drhafc91042008-02-21 02:09:45 +00003638** sqlite3_collation_needed16(). The second argument is the database
mihailimdc884822008-06-22 08:58:50 +00003639** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
3640** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
3641** sequence function required. The fourth parameter is the name of the
drhd68eee02009-12-11 03:44:18 +00003642** required collation sequence.)^
danielk19777cedc8d2004-06-10 10:50:08 +00003643**
drh6ed48bf2007-06-14 20:57:18 +00003644** The callback function should register the desired collation using
3645** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
3646** [sqlite3_create_collation_v2()].
danielk19777cedc8d2004-06-10 10:50:08 +00003647*/
3648int sqlite3_collation_needed(
3649 sqlite3*,
3650 void*,
3651 void(*)(void*,sqlite3*,int eTextRep,const char*)
3652);
3653int sqlite3_collation_needed16(
3654 sqlite3*,
3655 void*,
3656 void(*)(void*,sqlite3*,int eTextRep,const void*)
3657);
3658
drh2011d5f2004-07-22 02:40:37 +00003659/*
3660** Specify the key for an encrypted database. This routine should be
3661** called right after sqlite3_open().
3662**
3663** The code to implement this API is not available in the public release
3664** of SQLite.
3665*/
3666int sqlite3_key(
3667 sqlite3 *db, /* Database to be rekeyed */
3668 const void *pKey, int nKey /* The key */
3669);
3670
3671/*
3672** Change the key on an open database. If the current database is not
3673** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
3674** database is decrypted.
3675**
3676** The code to implement this API is not available in the public release
3677** of SQLite.
3678*/
3679int sqlite3_rekey(
3680 sqlite3 *db, /* Database to be rekeyed */
3681 const void *pKey, int nKey /* The new key */
3682);
danielk19770202b292004-06-09 09:55:16 +00003683
drhab3f9fe2004-08-14 17:10:10 +00003684/*
drhd68eee02009-12-11 03:44:18 +00003685** CAPI3REF: Suspend Execution For A Short Time
drh6ed48bf2007-06-14 20:57:18 +00003686**
drhd68eee02009-12-11 03:44:18 +00003687** ^The sqlite3_sleep() function causes the current thread to suspend execution
drhfddfa2d2007-12-05 18:05:16 +00003688** for at least a number of milliseconds specified in its parameter.
danielk1977600dd0b2005-01-20 01:14:23 +00003689**
drhd68eee02009-12-11 03:44:18 +00003690** ^If the operating system does not support sleep requests with
mihailimdc884822008-06-22 08:58:50 +00003691** millisecond time resolution, then the time will be rounded up to
drhd68eee02009-12-11 03:44:18 +00003692** the nearest second. ^The number of milliseconds of sleep actually
danielk1977600dd0b2005-01-20 01:14:23 +00003693** requested from the operating system is returned.
drh8bacf972007-08-25 16:21:29 +00003694**
drhd68eee02009-12-11 03:44:18 +00003695** ^SQLite implements this interface by calling the xSleep()
drhafc91042008-02-21 02:09:45 +00003696** method of the default [sqlite3_vfs] object.
danielk1977600dd0b2005-01-20 01:14:23 +00003697*/
3698int sqlite3_sleep(int);
3699
3700/*
drhd68eee02009-12-11 03:44:18 +00003701** CAPI3REF: Name Of The Folder Holding Temporary Files
drhd89bd002005-01-22 03:03:54 +00003702**
drhd68eee02009-12-11 03:44:18 +00003703** ^If this global variable is made to point to a string which is
shane26b34032008-05-23 17:21:09 +00003704** the name of a folder (a.k.a. directory), then all temporary files
drhd68eee02009-12-11 03:44:18 +00003705** created by SQLite when using a built-in [sqlite3_vfs | VFS]
3706** will be placed in that directory. ^If this variable
mihailimdc884822008-06-22 08:58:50 +00003707** is a NULL pointer, then SQLite performs a search for an appropriate
3708** temporary file directory.
drhab3f9fe2004-08-14 17:10:10 +00003709**
drh1a25f112009-04-06 15:55:03 +00003710** It is not safe to read or modify this variable in more than one
3711** thread at a time. It is not safe to read or modify this variable
3712** if a [database connection] is being used at the same time in a separate
3713** thread.
3714** It is intended that this variable be set once
drh4ff7fa02007-09-01 18:17:21 +00003715** as part of process initialization and before any SQLite interface
drh1a25f112009-04-06 15:55:03 +00003716** routines have been called and that this variable remain unchanged
3717** thereafter.
3718**
drhd68eee02009-12-11 03:44:18 +00003719** ^The [temp_store_directory pragma] may modify this variable and cause
3720** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
drh1a25f112009-04-06 15:55:03 +00003721** the [temp_store_directory pragma] always assumes that any string
3722** that this variable points to is held in memory obtained from
3723** [sqlite3_malloc] and the pragma may attempt to free that memory
3724** using [sqlite3_free].
3725** Hence, if this variable is modified directly, either it should be
3726** made NULL or made to point to memory obtained from [sqlite3_malloc]
3727** or else the use of the [temp_store_directory pragma] should be avoided.
drhab3f9fe2004-08-14 17:10:10 +00003728*/
drh73be5012007-08-08 12:11:21 +00003729SQLITE_EXTERN char *sqlite3_temp_directory;
drhab3f9fe2004-08-14 17:10:10 +00003730
danielk19776b456a22005-03-21 04:04:02 +00003731/*
drhd68eee02009-12-11 03:44:18 +00003732** CAPI3REF: Test For Auto-Commit Mode
mihailim15194222008-06-22 09:55:14 +00003733** KEYWORDS: {autocommit mode}
danielk19776b456a22005-03-21 04:04:02 +00003734**
drhd68eee02009-12-11 03:44:18 +00003735** ^The sqlite3_get_autocommit() interface returns non-zero or
drhf5befa02007-12-06 02:42:07 +00003736** zero if the given database connection is or is not in autocommit mode,
drhd68eee02009-12-11 03:44:18 +00003737** respectively. ^Autocommit mode is on by default.
3738** ^Autocommit mode is disabled by a [BEGIN] statement.
3739** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
drhe30f4422007-08-21 16:15:55 +00003740**
drh7c3472a2007-10-03 20:15:28 +00003741** If certain kinds of errors occur on a statement within a multi-statement
mihailimdc884822008-06-22 08:58:50 +00003742** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
drh7c3472a2007-10-03 20:15:28 +00003743** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
drh33c1be32008-01-30 16:16:14 +00003744** transaction might be rolled back automatically. The only way to
mihailimdc884822008-06-22 08:58:50 +00003745** find out whether SQLite automatically rolled back the transaction after
drh33c1be32008-01-30 16:16:14 +00003746** an error is to use this function.
drh7c3472a2007-10-03 20:15:28 +00003747**
drh8b39db12009-02-18 18:37:58 +00003748** If another thread changes the autocommit status of the database
3749** connection while this routine is running, then the return value
3750** is undefined.
drh3e1d8e62005-05-26 16:23:34 +00003751*/
3752int sqlite3_get_autocommit(sqlite3*);
3753
drh51942bc2005-06-12 22:01:42 +00003754/*
drhd68eee02009-12-11 03:44:18 +00003755** CAPI3REF: Find The Database Handle Of A Prepared Statement
drh6ed48bf2007-06-14 20:57:18 +00003756**
drhd68eee02009-12-11 03:44:18 +00003757** ^The sqlite3_db_handle interface returns the [database connection] handle
3758** to which a [prepared statement] belongs. ^The [database connection]
3759** returned by sqlite3_db_handle is the same [database connection]
3760** that was the first argument
mihailimdc884822008-06-22 08:58:50 +00003761** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
3762** create the statement in the first place.
drh51942bc2005-06-12 22:01:42 +00003763*/
3764sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
drh3e1d8e62005-05-26 16:23:34 +00003765
drhbb5a9c32008-06-19 02:52:25 +00003766/*
drhd68eee02009-12-11 03:44:18 +00003767** CAPI3REF: Find the next prepared statement
drhbb5a9c32008-06-19 02:52:25 +00003768**
drhd68eee02009-12-11 03:44:18 +00003769** ^This interface returns a pointer to the next [prepared statement] after
3770** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
mihailimdc884822008-06-22 08:58:50 +00003771** then this interface returns a pointer to the first prepared statement
drhd68eee02009-12-11 03:44:18 +00003772** associated with the database connection pDb. ^If no prepared statement
mihailimdc884822008-06-22 08:58:50 +00003773** satisfies the conditions of this routine, it returns NULL.
drhbb5a9c32008-06-19 02:52:25 +00003774**
drh8b39db12009-02-18 18:37:58 +00003775** The [database connection] pointer D in a call to
3776** [sqlite3_next_stmt(D,S)] must refer to an open database
3777** connection and in particular must not be a NULL pointer.
drhbb5a9c32008-06-19 02:52:25 +00003778*/
3779sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
3780
drhb37df7b2005-10-13 02:09:49 +00003781/*
drh9cd29642008-07-23 00:52:55 +00003782** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400>
drh6ed48bf2007-06-14 20:57:18 +00003783**
drhd68eee02009-12-11 03:44:18 +00003784** ^The sqlite3_commit_hook() interface registers a callback
drhabda6112009-05-14 22:37:47 +00003785** function to be invoked whenever a transaction is [COMMIT | committed].
drhd68eee02009-12-11 03:44:18 +00003786** ^Any callback set by a previous call to sqlite3_commit_hook()
drhf5befa02007-12-06 02:42:07 +00003787** for the same database connection is overridden.
drhd68eee02009-12-11 03:44:18 +00003788** ^The sqlite3_rollback_hook() interface registers a callback
drhabda6112009-05-14 22:37:47 +00003789** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
drhd68eee02009-12-11 03:44:18 +00003790** ^Any callback set by a previous call to sqlite3_rollback_hook()
drhf5befa02007-12-06 02:42:07 +00003791** for the same database connection is overridden.
drhd68eee02009-12-11 03:44:18 +00003792** ^The pArg argument is passed through to the callback.
3793** ^If the callback on a commit hook function returns non-zero,
mihailimdc884822008-06-22 08:58:50 +00003794** then the commit is converted into a rollback.
drh6ed48bf2007-06-14 20:57:18 +00003795**
drhd68eee02009-12-11 03:44:18 +00003796** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
3797** return the P argument from the previous call of the same function
3798** on the same [database connection] D, or NULL for
3799** the first call for each function on D.
drh6ed48bf2007-06-14 20:57:18 +00003800**
drhc8075422008-09-10 13:09:23 +00003801** The callback implementation must not do anything that will modify
3802** the database connection that invoked the callback. Any actions
3803** to modify the database connection must be deferred until after the
3804** completion of the [sqlite3_step()] call that triggered the commit
3805** or rollback hook in the first place.
3806** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3807** database connections for the meaning of "modify" in this paragraph.
3808**
drhd68eee02009-12-11 03:44:18 +00003809** ^Registering a NULL function disables the callback.
drh6ed48bf2007-06-14 20:57:18 +00003810**
drhd68eee02009-12-11 03:44:18 +00003811** ^When the commit hook callback routine returns zero, the [COMMIT]
3812** operation is allowed to continue normally. ^If the commit hook
drhabda6112009-05-14 22:37:47 +00003813** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
drhd68eee02009-12-11 03:44:18 +00003814** ^The rollback hook is invoked on a rollback that results from a commit
drhabda6112009-05-14 22:37:47 +00003815** hook returning non-zero, just as it would be with any other rollback.
3816**
drhd68eee02009-12-11 03:44:18 +00003817** ^For the purposes of this API, a transaction is said to have been
drh6ed48bf2007-06-14 20:57:18 +00003818** rolled back if an explicit "ROLLBACK" statement is executed, or
drhf5befa02007-12-06 02:42:07 +00003819** an error or constraint causes an implicit rollback to occur.
drhd68eee02009-12-11 03:44:18 +00003820** ^The rollback callback is not invoked if a transaction is
drhf5befa02007-12-06 02:42:07 +00003821** automatically rolled back because the database connection is closed.
drhd68eee02009-12-11 03:44:18 +00003822** ^The rollback callback is not invoked if a transaction is
drhf5befa02007-12-06 02:42:07 +00003823** rolled back because a commit callback returned non-zero.
drh6ed48bf2007-06-14 20:57:18 +00003824**
drhabda6112009-05-14 22:37:47 +00003825** See also the [sqlite3_update_hook()] interface.
drh6ed48bf2007-06-14 20:57:18 +00003826*/
3827void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
3828void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
3829
3830/*
drhd68eee02009-12-11 03:44:18 +00003831** CAPI3REF: Data Change Notification Callbacks
drh6ed48bf2007-06-14 20:57:18 +00003832**
drhd68eee02009-12-11 03:44:18 +00003833** ^The sqlite3_update_hook() interface registers a callback function
mihailimdc884822008-06-22 08:58:50 +00003834** with the [database connection] identified by the first argument
3835** to be invoked whenever a row is updated, inserted or deleted.
drhd68eee02009-12-11 03:44:18 +00003836** ^Any callback set by a previous call to this function
mihailimdc884822008-06-22 08:58:50 +00003837** for the same database connection is overridden.
danielk197794eb6a12005-12-15 15:22:08 +00003838**
drhd68eee02009-12-11 03:44:18 +00003839** ^The second argument is a pointer to the function to invoke when a
mihailimdc884822008-06-22 08:58:50 +00003840** row is updated, inserted or deleted.
drhd68eee02009-12-11 03:44:18 +00003841** ^The first argument to the callback is a copy of the third argument
mihailimdc884822008-06-22 08:58:50 +00003842** to sqlite3_update_hook().
drhd68eee02009-12-11 03:44:18 +00003843** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
mihailimdc884822008-06-22 08:58:50 +00003844** or [SQLITE_UPDATE], depending on the operation that caused the callback
3845** to be invoked.
drhd68eee02009-12-11 03:44:18 +00003846** ^The third and fourth arguments to the callback contain pointers to the
mihailimdc884822008-06-22 08:58:50 +00003847** database and table name containing the affected row.
drhd68eee02009-12-11 03:44:18 +00003848** ^The final callback parameter is the [rowid] of the row.
3849** ^In the case of an update, this is the [rowid] after the update takes place.
danielk197794eb6a12005-12-15 15:22:08 +00003850**
drhd68eee02009-12-11 03:44:18 +00003851** ^(The update hook is not invoked when internal system tables are
3852** modified (i.e. sqlite_master and sqlite_sequence).)^
danielk197771fd80b2005-12-16 06:54:01 +00003853**
drhd68eee02009-12-11 03:44:18 +00003854** ^In the current implementation, the update hook
drhabda6112009-05-14 22:37:47 +00003855** is not invoked when duplication rows are deleted because of an
drhd68eee02009-12-11 03:44:18 +00003856** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
drhabda6112009-05-14 22:37:47 +00003857** invoked when rows are deleted using the [truncate optimization].
3858** The exceptions defined in this paragraph might change in a future
3859** release of SQLite.
3860**
drhc8075422008-09-10 13:09:23 +00003861** The update hook implementation must not do anything that will modify
3862** the database connection that invoked the update hook. Any actions
3863** to modify the database connection must be deferred until after the
3864** completion of the [sqlite3_step()] call that triggered the update hook.
3865** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3866** database connections for the meaning of "modify" in this paragraph.
3867**
drhd68eee02009-12-11 03:44:18 +00003868** ^The sqlite3_update_hook(D,C,P) function
3869** returns the P argument from the previous call
3870** on the same [database connection] D, or NULL for
3871** the first call on D.
drhafc91042008-02-21 02:09:45 +00003872**
drhabda6112009-05-14 22:37:47 +00003873** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
3874** interfaces.
danielk197794eb6a12005-12-15 15:22:08 +00003875*/
danielk197771fd80b2005-12-16 06:54:01 +00003876void *sqlite3_update_hook(
danielk197794eb6a12005-12-15 15:22:08 +00003877 sqlite3*,
drh6d2069d2007-08-14 01:58:53 +00003878 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
danielk197794eb6a12005-12-15 15:22:08 +00003879 void*
3880);
danielk197713a68c32005-12-15 10:11:30 +00003881
danielk1977f3f06bb2005-12-16 15:24:28 +00003882/*
drhd68eee02009-12-11 03:44:18 +00003883** CAPI3REF: Enable Or Disable Shared Pager Cache
drhe33b0ed2009-08-06 17:40:45 +00003884** KEYWORDS: {shared cache}
danielk1977f3f06bb2005-12-16 15:24:28 +00003885**
drhd68eee02009-12-11 03:44:18 +00003886** ^(This routine enables or disables the sharing of the database cache
mihailimdc884822008-06-22 08:58:50 +00003887** and schema data structures between [database connection | connections]
3888** to the same database. Sharing is enabled if the argument is true
drhd68eee02009-12-11 03:44:18 +00003889** and disabled if the argument is false.)^
danielk1977f3f06bb2005-12-16 15:24:28 +00003890**
drhd68eee02009-12-11 03:44:18 +00003891** ^Cache sharing is enabled and disabled for an entire process.
mihailimdc884822008-06-22 08:58:50 +00003892** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
3893** sharing was enabled or disabled for each thread separately.
drh6ed48bf2007-06-14 20:57:18 +00003894**
drhd68eee02009-12-11 03:44:18 +00003895** ^(The cache sharing mode set by this interface effects all subsequent
drhe30f4422007-08-21 16:15:55 +00003896** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
drhafc91042008-02-21 02:09:45 +00003897** Existing database connections continue use the sharing mode
drhd68eee02009-12-11 03:44:18 +00003898** that was in effect at the time they were opened.)^
drh6ed48bf2007-06-14 20:57:18 +00003899**
drhd68eee02009-12-11 03:44:18 +00003900** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
3901** successfully. An [error code] is returned otherwise.)^
drh6ed48bf2007-06-14 20:57:18 +00003902**
drhd68eee02009-12-11 03:44:18 +00003903** ^Shared cache is disabled by default. But this might change in
drh4ff7fa02007-09-01 18:17:21 +00003904** future releases of SQLite. Applications that care about shared
3905** cache setting should set it explicitly.
drhafc91042008-02-21 02:09:45 +00003906**
drhaff46972009-02-12 17:07:34 +00003907** See Also: [SQLite Shared-Cache Mode]
danielk1977aef0bf62005-12-30 16:28:01 +00003908*/
3909int sqlite3_enable_shared_cache(int);
3910
3911/*
drhd68eee02009-12-11 03:44:18 +00003912** CAPI3REF: Attempt To Free Heap Memory
drh6ed48bf2007-06-14 20:57:18 +00003913**
drhd68eee02009-12-11 03:44:18 +00003914** ^The sqlite3_release_memory() interface attempts to free N bytes
mihailim04bcc002008-06-22 10:21:27 +00003915** of heap memory by deallocating non-essential memory allocations
drhd68eee02009-12-11 03:44:18 +00003916** held by the database library. Memory used to cache database
mihailim04bcc002008-06-22 10:21:27 +00003917** pages to improve performance is an example of non-essential memory.
drhd68eee02009-12-11 03:44:18 +00003918** ^sqlite3_release_memory() returns the number of bytes actually freed,
mihailim04bcc002008-06-22 10:21:27 +00003919** which might be more or less than the amount requested.
danielk197752622822006-01-09 09:59:49 +00003920*/
3921int sqlite3_release_memory(int);
3922
3923/*
drhd68eee02009-12-11 03:44:18 +00003924** CAPI3REF: Impose A Limit On Heap Size
drh6ed48bf2007-06-14 20:57:18 +00003925**
drhd68eee02009-12-11 03:44:18 +00003926** ^The sqlite3_soft_heap_limit() interface places a "soft" limit
mihailimdc884822008-06-22 08:58:50 +00003927** on the amount of heap memory that may be allocated by SQLite.
drhd68eee02009-12-11 03:44:18 +00003928** ^If an internal allocation is requested that would exceed the
mihailimdc884822008-06-22 08:58:50 +00003929** soft heap limit, [sqlite3_release_memory()] is invoked one or
3930** more times to free up some space before the allocation is performed.
danielk197752622822006-01-09 09:59:49 +00003931**
drhd68eee02009-12-11 03:44:18 +00003932** ^The limit is called "soft", because if [sqlite3_release_memory()]
mihailimdc884822008-06-22 08:58:50 +00003933** cannot free sufficient memory to prevent the limit from being exceeded,
drhe30f4422007-08-21 16:15:55 +00003934** the memory is allocated anyway and the current operation proceeds.
drh6ed48bf2007-06-14 20:57:18 +00003935**
drhd68eee02009-12-11 03:44:18 +00003936** ^A negative or zero value for N means that there is no soft heap limit and
drhe30f4422007-08-21 16:15:55 +00003937** [sqlite3_release_memory()] will only be called when memory is exhausted.
drhd68eee02009-12-11 03:44:18 +00003938** ^The default value for the soft heap limit is zero.
drh6ed48bf2007-06-14 20:57:18 +00003939**
drhd68eee02009-12-11 03:44:18 +00003940** ^(SQLite makes a best effort to honor the soft heap limit.
shane26b34032008-05-23 17:21:09 +00003941** But if the soft heap limit cannot be honored, execution will
drhd68eee02009-12-11 03:44:18 +00003942** continue without error or notification.)^ This is why the limit is
drh6ed48bf2007-06-14 20:57:18 +00003943** called a "soft" limit. It is advisory only.
3944**
drhe30f4422007-08-21 16:15:55 +00003945** Prior to SQLite version 3.5.0, this routine only constrained the memory
3946** allocated by a single thread - the same thread in which this routine
3947** runs. Beginning with SQLite version 3.5.0, the soft heap limit is
drhafc91042008-02-21 02:09:45 +00003948** applied to all threads. The value specified for the soft heap limit
3949** is an upper bound on the total memory allocation for all threads. In
drh8bacf972007-08-25 16:21:29 +00003950** version 3.5.0 there is no mechanism for limiting the heap usage for
3951** individual threads.
danielk197752622822006-01-09 09:59:49 +00003952*/
drhd2d4a6b2006-01-10 15:18:27 +00003953void sqlite3_soft_heap_limit(int);
danielk197752622822006-01-09 09:59:49 +00003954
3955/*
drh9cd29642008-07-23 00:52:55 +00003956** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300>
drh6ed48bf2007-06-14 20:57:18 +00003957**
drhd68eee02009-12-11 03:44:18 +00003958** ^This routine returns metadata about a specific column of a specific
mihailimdc884822008-06-22 08:58:50 +00003959** database table accessible using the [database connection] handle
3960** passed as the first function argument.
danielk1977deb802c2006-02-09 13:43:28 +00003961**
drhd68eee02009-12-11 03:44:18 +00003962** ^The column is identified by the second, third and fourth parameters to
3963** this function. ^(The second parameter is either the name of the database
danielk1977deb802c2006-02-09 13:43:28 +00003964** (i.e. "main", "temp" or an attached database) containing the specified
3965** table or NULL. If it is NULL, then all attached databases are searched
mihailimdc884822008-06-22 08:58:50 +00003966** for the table using the same algorithm used by the database engine to
drhd68eee02009-12-11 03:44:18 +00003967** resolve unqualified table references.)^
danielk1977deb802c2006-02-09 13:43:28 +00003968**
drhd68eee02009-12-11 03:44:18 +00003969** ^The third and fourth parameters to this function are the table and column
mihailimdc884822008-06-22 08:58:50 +00003970** name of the desired column, respectively. Neither of these parameters
danielk1977deb802c2006-02-09 13:43:28 +00003971** may be NULL.
3972**
drhd68eee02009-12-11 03:44:18 +00003973** ^Metadata is returned by writing to the memory locations passed as the 5th
3974** and subsequent parameters to this function. ^Any of these arguments may be
mihailimdc884822008-06-22 08:58:50 +00003975** NULL, in which case the corresponding element of metadata is omitted.
mihailim15194222008-06-22 09:55:14 +00003976**
drhd68eee02009-12-11 03:44:18 +00003977** ^(<blockquote>
mihailimdc884822008-06-22 08:58:50 +00003978** <table border="1">
3979** <tr><th> Parameter <th> Output<br>Type <th> Description
danielk1977deb802c2006-02-09 13:43:28 +00003980**
mihailimdc884822008-06-22 08:58:50 +00003981** <tr><td> 5th <td> const char* <td> Data type
3982** <tr><td> 6th <td> const char* <td> Name of default collation sequence
3983** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
3984** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
drh49c3d572008-12-15 22:51:38 +00003985** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
mihailimdc884822008-06-22 08:58:50 +00003986** </table>
drhd68eee02009-12-11 03:44:18 +00003987** </blockquote>)^
danielk1977deb802c2006-02-09 13:43:28 +00003988**
drhd68eee02009-12-11 03:44:18 +00003989** ^The memory pointed to by the character pointers returned for the
mihailimdc884822008-06-22 08:58:50 +00003990** declaration type and collation sequence is valid only until the next
3991** call to any SQLite API function.
danielk1977deb802c2006-02-09 13:43:28 +00003992**
drhd68eee02009-12-11 03:44:18 +00003993** ^If the specified table is actually a view, an [error code] is returned.
danielk1977deb802c2006-02-09 13:43:28 +00003994**
drhd68eee02009-12-11 03:44:18 +00003995** ^If the specified column is "rowid", "oid" or "_rowid_" and an
drh49c3d572008-12-15 22:51:38 +00003996** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
drhd68eee02009-12-11 03:44:18 +00003997** parameters are set for the explicitly declared column. ^(If there is no
drh49c3d572008-12-15 22:51:38 +00003998** explicitly declared [INTEGER PRIMARY KEY] column, then the output
mihailimdc884822008-06-22 08:58:50 +00003999** parameters are set as follows:
danielk1977deb802c2006-02-09 13:43:28 +00004000**
drh6ed48bf2007-06-14 20:57:18 +00004001** <pre>
danielk1977deb802c2006-02-09 13:43:28 +00004002** data type: "INTEGER"
4003** collation sequence: "BINARY"
4004** not null: 0
4005** primary key: 1
4006** auto increment: 0
drhd68eee02009-12-11 03:44:18 +00004007** </pre>)^
danielk1977deb802c2006-02-09 13:43:28 +00004008**
drhd68eee02009-12-11 03:44:18 +00004009** ^(This function may load one or more schemas from database files. If an
danielk1977deb802c2006-02-09 13:43:28 +00004010** error occurs during this process, or if the requested table or column
mihailimdc884822008-06-22 08:58:50 +00004011** cannot be found, an [error code] is returned and an error message left
drhd68eee02009-12-11 03:44:18 +00004012** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
danielk19774b1ae992006-02-10 03:06:10 +00004013**
drhd68eee02009-12-11 03:44:18 +00004014** ^This API is only available if the library was compiled with the
drh4ead1482008-06-26 18:16:05 +00004015** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
danielk1977deb802c2006-02-09 13:43:28 +00004016*/
4017int sqlite3_table_column_metadata(
4018 sqlite3 *db, /* Connection handle */
4019 const char *zDbName, /* Database name or NULL */
4020 const char *zTableName, /* Table name */
4021 const char *zColumnName, /* Column name */
4022 char const **pzDataType, /* OUTPUT: Declared data type */
4023 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
4024 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
4025 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
drh98c94802007-10-01 13:50:31 +00004026 int *pAutoinc /* OUTPUT: True if column is auto-increment */
danielk1977deb802c2006-02-09 13:43:28 +00004027);
4028
4029/*
drhd68eee02009-12-11 03:44:18 +00004030** CAPI3REF: Load An Extension
drh1e397f82006-06-08 15:28:43 +00004031**
drhd68eee02009-12-11 03:44:18 +00004032** ^This interface loads an SQLite extension library from the named file.
drh1e397f82006-06-08 15:28:43 +00004033**
drhd68eee02009-12-11 03:44:18 +00004034** ^The sqlite3_load_extension() interface attempts to load an
4035** SQLite extension library contained in the file zFile.
drh1e397f82006-06-08 15:28:43 +00004036**
drhd68eee02009-12-11 03:44:18 +00004037** ^The entry point is zProc.
4038** ^zProc may be 0, in which case the name of the entry point
4039** defaults to "sqlite3_extension_init".
4040** ^The sqlite3_load_extension() interface returns
4041** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
4042** ^If an error occurs and pzErrMsg is not 0, then the
4043** [sqlite3_load_extension()] interface shall attempt to
4044** fill *pzErrMsg with error message text stored in memory
4045** obtained from [sqlite3_malloc()]. The calling function
4046** should free this memory by calling [sqlite3_free()].
mihailimdc884822008-06-22 08:58:50 +00004047**
drhd68eee02009-12-11 03:44:18 +00004048** ^Extension loading must be enabled using
4049** [sqlite3_enable_load_extension()] prior to calling this API,
4050** otherwise an error will be returned.
drha94cc422009-12-03 01:01:02 +00004051**
4052** See also the [load_extension() SQL function].
drh1e397f82006-06-08 15:28:43 +00004053*/
4054int sqlite3_load_extension(
4055 sqlite3 *db, /* Load the extension into this database connection */
4056 const char *zFile, /* Name of the shared library containing extension */
4057 const char *zProc, /* Entry point. Derived from zFile if 0 */
4058 char **pzErrMsg /* Put error message here if not 0 */
4059);
4060
4061/*
drhd68eee02009-12-11 03:44:18 +00004062** CAPI3REF: Enable Or Disable Extension Loading
drh6ed48bf2007-06-14 20:57:18 +00004063**
drhd68eee02009-12-11 03:44:18 +00004064** ^So as not to open security holes in older applications that are
drh6ed48bf2007-06-14 20:57:18 +00004065** unprepared to deal with extension loading, and as a means of disabling
mihailimdc884822008-06-22 08:58:50 +00004066** extension loading while evaluating user-entered SQL, the following API
4067** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
drhc2e87a32006-06-27 15:16:14 +00004068**
drhd68eee02009-12-11 03:44:18 +00004069** ^Extension loading is off by default. See ticket #1863.
4070** ^Call the sqlite3_enable_load_extension() routine with onoff==1
4071** to turn extension loading on and call it with onoff==0 to turn
4072** it back off again.
drhc2e87a32006-06-27 15:16:14 +00004073*/
4074int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
4075
4076/*
drhd68eee02009-12-11 03:44:18 +00004077** CAPI3REF: Automatically Load An Extensions
drh9eff6162006-06-12 21:59:13 +00004078**
drhd68eee02009-12-11 03:44:18 +00004079** ^This API can be invoked at program startup in order to register
drh1409be62006-08-23 20:07:20 +00004080** one or more statically linked extensions that will be available
drhd68eee02009-12-11 03:44:18 +00004081** to all new [database connections].
mihailimdc884822008-06-22 08:58:50 +00004082**
drhd68eee02009-12-11 03:44:18 +00004083** ^(This routine stores a pointer to the extension entry point
4084** in an array that is obtained from [sqlite3_malloc()]. That memory
4085** is deallocated by [sqlite3_reset_auto_extension()].)^
mihailimdc884822008-06-22 08:58:50 +00004086**
drhd68eee02009-12-11 03:44:18 +00004087** ^This function registers an extension entry point that is
4088** automatically invoked whenever a new [database connection]
4089** is opened using [sqlite3_open()], [sqlite3_open16()],
4090** or [sqlite3_open_v2()].
4091** ^Duplicate extensions are detected so calling this routine
4092** multiple times with the same extension is harmless.
4093** ^Automatic extensions apply across all threads.
drh1409be62006-08-23 20:07:20 +00004094*/
drh1875f7a2008-12-08 18:19:17 +00004095int sqlite3_auto_extension(void (*xEntryPoint)(void));
drh1409be62006-08-23 20:07:20 +00004096
drh1409be62006-08-23 20:07:20 +00004097/*
drhd68eee02009-12-11 03:44:18 +00004098** CAPI3REF: Reset Automatic Extension Loading
drh1409be62006-08-23 20:07:20 +00004099**
drhd68eee02009-12-11 03:44:18 +00004100** ^(This function disables all previously registered automatic
4101** extensions. It undoes the effect of all prior
4102** [sqlite3_auto_extension()] calls.)^
drh6ed48bf2007-06-14 20:57:18 +00004103**
drhd68eee02009-12-11 03:44:18 +00004104** ^This function disables automatic extensions in all threads.
drh1409be62006-08-23 20:07:20 +00004105*/
4106void sqlite3_reset_auto_extension(void);
4107
drh1409be62006-08-23 20:07:20 +00004108/*
4109****** EXPERIMENTAL - subject to change without notice **************
4110**
drh9eff6162006-06-12 21:59:13 +00004111** The interface to the virtual-table mechanism is currently considered
4112** to be experimental. The interface might change in incompatible ways.
4113** If this is a problem for you, do not use the interface at this time.
4114**
shane26b34032008-05-23 17:21:09 +00004115** When the virtual-table mechanism stabilizes, we will declare the
drh9eff6162006-06-12 21:59:13 +00004116** interface fixed, support it indefinitely, and remove this comment.
4117*/
4118
4119/*
4120** Structures used by the virtual table interface
drhe09daa92006-06-10 13:29:31 +00004121*/
4122typedef struct sqlite3_vtab sqlite3_vtab;
4123typedef struct sqlite3_index_info sqlite3_index_info;
4124typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
4125typedef struct sqlite3_module sqlite3_module;
drh9eff6162006-06-12 21:59:13 +00004126
4127/*
drhd68eee02009-12-11 03:44:18 +00004128** CAPI3REF: Virtual Table Object
drh9cff9dc2009-04-13 14:43:40 +00004129** KEYWORDS: sqlite3_module {virtual table module}
drhd5a68d32008-08-04 13:44:57 +00004130** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004131**
drh9cff9dc2009-04-13 14:43:40 +00004132** This structure, sometimes called a a "virtual table module",
4133** defines the implementation of a [virtual tables].
4134** This structure consists mostly of methods for the module.
mihailim15194222008-06-22 09:55:14 +00004135**
drhd68eee02009-12-11 03:44:18 +00004136** ^A virtual table module is created by filling in a persistent
drh9cff9dc2009-04-13 14:43:40 +00004137** instance of this structure and passing a pointer to that instance
4138** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
drhd68eee02009-12-11 03:44:18 +00004139** ^The registration remains valid until it is replaced by a different
drh9cff9dc2009-04-13 14:43:40 +00004140** module or until the [database connection] closes. The content
4141** of this structure must not change while it is registered with
4142** any database connection.
drh9eff6162006-06-12 21:59:13 +00004143*/
drhe09daa92006-06-10 13:29:31 +00004144struct sqlite3_module {
4145 int iVersion;
danielk19779da9d472006-06-14 06:58:15 +00004146 int (*xCreate)(sqlite3*, void *pAux,
drhe4102962006-09-11 00:34:22 +00004147 int argc, const char *const*argv,
drh4ca8aac2006-09-10 17:31:58 +00004148 sqlite3_vtab **ppVTab, char**);
danielk19779da9d472006-06-14 06:58:15 +00004149 int (*xConnect)(sqlite3*, void *pAux,
drhe4102962006-09-11 00:34:22 +00004150 int argc, const char *const*argv,
drh4ca8aac2006-09-10 17:31:58 +00004151 sqlite3_vtab **ppVTab, char**);
drhe09daa92006-06-10 13:29:31 +00004152 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
4153 int (*xDisconnect)(sqlite3_vtab *pVTab);
4154 int (*xDestroy)(sqlite3_vtab *pVTab);
4155 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
4156 int (*xClose)(sqlite3_vtab_cursor*);
drh4be8b512006-06-13 23:51:34 +00004157 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
drhe09daa92006-06-10 13:29:31 +00004158 int argc, sqlite3_value **argv);
4159 int (*xNext)(sqlite3_vtab_cursor*);
danielk1977a298e902006-06-22 09:53:48 +00004160 int (*xEof)(sqlite3_vtab_cursor*);
drhe09daa92006-06-10 13:29:31 +00004161 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
drh6d2069d2007-08-14 01:58:53 +00004162 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
4163 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
drhe09daa92006-06-10 13:29:31 +00004164 int (*xBegin)(sqlite3_vtab *pVTab);
4165 int (*xSync)(sqlite3_vtab *pVTab);
4166 int (*xCommit)(sqlite3_vtab *pVTab);
4167 int (*xRollback)(sqlite3_vtab *pVTab);
drhb7f6f682006-07-08 17:06:43 +00004168 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
drhe94b0c32006-07-08 18:09:15 +00004169 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
4170 void **ppArg);
danielk1977182c4ba2007-06-27 15:53:34 +00004171 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
drhe09daa92006-06-10 13:29:31 +00004172};
drh9eff6162006-06-12 21:59:13 +00004173
4174/*
drhd68eee02009-12-11 03:44:18 +00004175** CAPI3REF: Virtual Table Indexing Information
drhb4d58ae2008-02-21 20:17:06 +00004176** KEYWORDS: sqlite3_index_info
drhd5a68d32008-08-04 13:44:57 +00004177** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004178**
drh9eff6162006-06-12 21:59:13 +00004179** The sqlite3_index_info structure and its substructures is used to
drh9cff9dc2009-04-13 14:43:40 +00004180** pass information into and receive the reply from the [xBestIndex]
4181** method of a [virtual table module]. The fields under **Inputs** are the
drh9eff6162006-06-12 21:59:13 +00004182** inputs to xBestIndex and are read-only. xBestIndex inserts its
4183** results into the **Outputs** fields.
4184**
drhd68eee02009-12-11 03:44:18 +00004185** ^(The aConstraint[] array records WHERE clause constraints of the form:
drh9eff6162006-06-12 21:59:13 +00004186**
mihailim15194222008-06-22 09:55:14 +00004187** <pre>column OP expr</pre>
drh9eff6162006-06-12 21:59:13 +00004188**
drhd68eee02009-12-11 03:44:18 +00004189** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^The particular operator is
4190** stored in aConstraint[].op. ^The index of the column is stored in
4191** aConstraint[].iColumn. ^(aConstraint[].usable is TRUE if the
drh9eff6162006-06-12 21:59:13 +00004192** expr on the right-hand side can be evaluated (and thus the constraint
drhd68eee02009-12-11 03:44:18 +00004193** is usable) and false if it cannot.)^
drh9eff6162006-06-12 21:59:13 +00004194**
drhd68eee02009-12-11 03:44:18 +00004195** ^The optimizer automatically inverts terms of the form "expr OP column"
drh98c94802007-10-01 13:50:31 +00004196** and makes other simplifications to the WHERE clause in an attempt to
drh9eff6162006-06-12 21:59:13 +00004197** get as many WHERE clause terms into the form shown above as possible.
drhd68eee02009-12-11 03:44:18 +00004198** ^The aConstraint[] array only reports WHERE clause terms in the correct
drh9eff6162006-06-12 21:59:13 +00004199** form that refer to the particular virtual table being queried.
4200**
drhd68eee02009-12-11 03:44:18 +00004201** ^Information about the ORDER BY clause is stored in aOrderBy[].
4202** ^Each term of aOrderBy records a column of the ORDER BY clause.
drh9eff6162006-06-12 21:59:13 +00004203**
drh9cff9dc2009-04-13 14:43:40 +00004204** The [xBestIndex] method must fill aConstraintUsage[] with information
drhd68eee02009-12-11 03:44:18 +00004205** about what parameters to pass to xFilter. ^If argvIndex>0 then
drh9eff6162006-06-12 21:59:13 +00004206** the right-hand side of the corresponding aConstraint[] is evaluated
drhd68eee02009-12-11 03:44:18 +00004207** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
drh9eff6162006-06-12 21:59:13 +00004208** is true, then the constraint is assumed to be fully handled by the
drhd68eee02009-12-11 03:44:18 +00004209** virtual table and is not checked again by SQLite.)^
drh9eff6162006-06-12 21:59:13 +00004210**
drhd68eee02009-12-11 03:44:18 +00004211** ^The idxNum and idxPtr values are recorded and passed into the
drh9cff9dc2009-04-13 14:43:40 +00004212** [xFilter] method.
drhd68eee02009-12-11 03:44:18 +00004213** ^[sqlite3_free()] is used to free idxPtr if and only iff
drh9cff9dc2009-04-13 14:43:40 +00004214** needToFreeIdxPtr is true.
drh9eff6162006-06-12 21:59:13 +00004215**
drhd68eee02009-12-11 03:44:18 +00004216** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
drh9eff6162006-06-12 21:59:13 +00004217** the correct order to satisfy the ORDER BY clause so that no separate
4218** sorting step is required.
4219**
drhd68eee02009-12-11 03:44:18 +00004220** ^The estimatedCost value is an estimate of the cost of doing the
drh9eff6162006-06-12 21:59:13 +00004221** particular lookup. A full scan of a table with N entries should have
4222** a cost of N. A binary search of a table of N entries should have a
4223** cost of approximately log(N).
4224*/
drhe09daa92006-06-10 13:29:31 +00004225struct sqlite3_index_info {
4226 /* Inputs */
drh6cca08c2007-09-21 12:43:16 +00004227 int nConstraint; /* Number of entries in aConstraint */
4228 struct sqlite3_index_constraint {
drh9eff6162006-06-12 21:59:13 +00004229 int iColumn; /* Column on left-hand side of constraint */
4230 unsigned char op; /* Constraint operator */
4231 unsigned char usable; /* True if this constraint is usable */
4232 int iTermOffset; /* Used internally - xBestIndex should ignore */
drh6cca08c2007-09-21 12:43:16 +00004233 } *aConstraint; /* Table of WHERE clause constraints */
4234 int nOrderBy; /* Number of terms in the ORDER BY clause */
4235 struct sqlite3_index_orderby {
drh9eff6162006-06-12 21:59:13 +00004236 int iColumn; /* Column number */
4237 unsigned char desc; /* True for DESC. False for ASC. */
drh6cca08c2007-09-21 12:43:16 +00004238 } *aOrderBy; /* The ORDER BY clause */
drhe09daa92006-06-10 13:29:31 +00004239 /* Outputs */
drh9eff6162006-06-12 21:59:13 +00004240 struct sqlite3_index_constraint_usage {
4241 int argvIndex; /* if >0, constraint is part of argv to xFilter */
4242 unsigned char omit; /* Do not code a test for this constraint */
drh6cca08c2007-09-21 12:43:16 +00004243 } *aConstraintUsage;
drh4be8b512006-06-13 23:51:34 +00004244 int idxNum; /* Number used to identify the index */
4245 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
4246 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
drh9eff6162006-06-12 21:59:13 +00004247 int orderByConsumed; /* True if output is already ordered */
4248 double estimatedCost; /* Estimated cost of using this index */
drhe09daa92006-06-10 13:29:31 +00004249};
drh9eff6162006-06-12 21:59:13 +00004250#define SQLITE_INDEX_CONSTRAINT_EQ 2
4251#define SQLITE_INDEX_CONSTRAINT_GT 4
4252#define SQLITE_INDEX_CONSTRAINT_LE 8
4253#define SQLITE_INDEX_CONSTRAINT_LT 16
4254#define SQLITE_INDEX_CONSTRAINT_GE 32
4255#define SQLITE_INDEX_CONSTRAINT_MATCH 64
4256
4257/*
drhd68eee02009-12-11 03:44:18 +00004258** CAPI3REF: Register A Virtual Table Implementation
drhd5a68d32008-08-04 13:44:57 +00004259** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004260**
drhd68eee02009-12-11 03:44:18 +00004261** ^This routine is used to register a new [virtual table module] name.
4262** ^Module names must be registered before
drh9cff9dc2009-04-13 14:43:40 +00004263** creating a new [virtual table] using the module, or before using a
4264** preexisting [virtual table] for the module.
mihailim15194222008-06-22 09:55:14 +00004265**
drhd68eee02009-12-11 03:44:18 +00004266** ^The module name is registered on the [database connection] specified
4267** by the first parameter. ^The name of the module is given by the
4268** second parameter. ^The third parameter is a pointer to
4269** the implementation of the [virtual table module]. ^The fourth
drh9cff9dc2009-04-13 14:43:40 +00004270** parameter is an arbitrary client data pointer that is passed through
4271** into the [xCreate] and [xConnect] methods of the virtual table module
4272** when a new virtual table is be being created or reinitialized.
4273**
drhd68eee02009-12-11 03:44:18 +00004274** ^This interface has exactly the same effect as calling
drh9cff9dc2009-04-13 14:43:40 +00004275** [sqlite3_create_module_v2()] with a NULL client data destructor.
drh9eff6162006-06-12 21:59:13 +00004276*/
shanea79c3cc2008-08-11 17:27:01 +00004277SQLITE_EXPERIMENTAL int sqlite3_create_module(
drh9eff6162006-06-12 21:59:13 +00004278 sqlite3 *db, /* SQLite connection to register module with */
4279 const char *zName, /* Name of the module */
drh9cff9dc2009-04-13 14:43:40 +00004280 const sqlite3_module *p, /* Methods for the module */
4281 void *pClientData /* Client data for xCreate/xConnect */
drhb9bb7c12006-06-11 23:41:55 +00004282);
drhe09daa92006-06-10 13:29:31 +00004283
drh9eff6162006-06-12 21:59:13 +00004284/*
drhd68eee02009-12-11 03:44:18 +00004285** CAPI3REF: Register A Virtual Table Implementation
drhd5a68d32008-08-04 13:44:57 +00004286** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004287**
drhd68eee02009-12-11 03:44:18 +00004288** ^This routine is identical to the [sqlite3_create_module()] method,
drh9cff9dc2009-04-13 14:43:40 +00004289** except that it has an extra parameter to specify
drhd68eee02009-12-11 03:44:18 +00004290** a destructor function for the client data pointer. ^SQLite will
drh9cff9dc2009-04-13 14:43:40 +00004291** invoke the destructor function (if it is not NULL) when SQLite
4292** no longer needs the pClientData pointer.
danielk1977832a58a2007-06-22 15:21:15 +00004293*/
shanea79c3cc2008-08-11 17:27:01 +00004294SQLITE_EXPERIMENTAL int sqlite3_create_module_v2(
danielk1977832a58a2007-06-22 15:21:15 +00004295 sqlite3 *db, /* SQLite connection to register module with */
4296 const char *zName, /* Name of the module */
drh9cff9dc2009-04-13 14:43:40 +00004297 const sqlite3_module *p, /* Methods for the module */
4298 void *pClientData, /* Client data for xCreate/xConnect */
danielk1977832a58a2007-06-22 15:21:15 +00004299 void(*xDestroy)(void*) /* Module destructor function */
4300);
4301
4302/*
drhd68eee02009-12-11 03:44:18 +00004303** CAPI3REF: Virtual Table Instance Object
drhb4d58ae2008-02-21 20:17:06 +00004304** KEYWORDS: sqlite3_vtab
drhd5a68d32008-08-04 13:44:57 +00004305** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004306**
drh9cff9dc2009-04-13 14:43:40 +00004307** Every [virtual table module] implementation uses a subclass
drhd68eee02009-12-11 03:44:18 +00004308** of this object to describe a particular instance
drh9cff9dc2009-04-13 14:43:40 +00004309** of the [virtual table]. Each subclass will
mihailim15194222008-06-22 09:55:14 +00004310** be tailored to the specific needs of the module implementation.
4311** The purpose of this superclass is to define certain fields that are
4312** common to all module implementations.
drhfe1368e2006-09-10 17:08:29 +00004313**
drhd68eee02009-12-11 03:44:18 +00004314** ^Virtual tables methods can set an error message by assigning a
mihailim15194222008-06-22 09:55:14 +00004315** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
4316** take care that any prior string is freed by a call to [sqlite3_free()]
drhd68eee02009-12-11 03:44:18 +00004317** prior to assigning a new string to zErrMsg. ^After the error message
drhfe1368e2006-09-10 17:08:29 +00004318** is delivered up to the client application, the string will be automatically
drh9cff9dc2009-04-13 14:43:40 +00004319** freed by sqlite3_free() and the zErrMsg field will be zeroed.
drh9eff6162006-06-12 21:59:13 +00004320*/
4321struct sqlite3_vtab {
drha967e882006-06-13 01:04:52 +00004322 const sqlite3_module *pModule; /* The module for this virtual table */
danielk1977595a5232009-07-24 17:58:53 +00004323 int nRef; /* NO LONGER USED */
drh4ca8aac2006-09-10 17:31:58 +00004324 char *zErrMsg; /* Error message from sqlite3_mprintf() */
drh9eff6162006-06-12 21:59:13 +00004325 /* Virtual table implementations will typically add additional fields */
4326};
4327
drhb4d58ae2008-02-21 20:17:06 +00004328/*
drhd68eee02009-12-11 03:44:18 +00004329** CAPI3REF: Virtual Table Cursor Object
drh9cff9dc2009-04-13 14:43:40 +00004330** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
drhd5a68d32008-08-04 13:44:57 +00004331** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004332**
drh9cff9dc2009-04-13 14:43:40 +00004333** Every [virtual table module] implementation uses a subclass of the
4334** following structure to describe cursors that point into the
4335** [virtual table] and are used
drh9eff6162006-06-12 21:59:13 +00004336** to loop through the virtual table. Cursors are created using the
drh9cff9dc2009-04-13 14:43:40 +00004337** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
drhd68eee02009-12-11 03:44:18 +00004338** by the [sqlite3_module.xClose | xClose] method. Cursors are used
drh9cff9dc2009-04-13 14:43:40 +00004339** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
4340** of the module. Each module implementation will define
drh9eff6162006-06-12 21:59:13 +00004341** the content of a cursor structure to suit its own needs.
4342**
4343** This superclass exists in order to define fields of the cursor that
4344** are common to all implementations.
4345*/
4346struct sqlite3_vtab_cursor {
4347 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
4348 /* Virtual table implementations will typically add additional fields */
4349};
4350
4351/*
drhd68eee02009-12-11 03:44:18 +00004352** CAPI3REF: Declare The Schema Of A Virtual Table
drhd5a68d32008-08-04 13:44:57 +00004353** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004354**
drhd68eee02009-12-11 03:44:18 +00004355** ^The [xCreate] and [xConnect] methods of a
drh9cff9dc2009-04-13 14:43:40 +00004356** [virtual table module] call this interface
drh9eff6162006-06-12 21:59:13 +00004357** to declare the format (the names and datatypes of the columns) of
4358** the virtual tables they implement.
4359*/
drh9cff9dc2009-04-13 14:43:40 +00004360SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
drhe09daa92006-06-10 13:29:31 +00004361
4362/*
drhd68eee02009-12-11 03:44:18 +00004363** CAPI3REF: Overload A Function For A Virtual Table
drhd5a68d32008-08-04 13:44:57 +00004364** EXPERIMENTAL
drhb4d58ae2008-02-21 20:17:06 +00004365**
drhd68eee02009-12-11 03:44:18 +00004366** ^(Virtual tables can provide alternative implementations of functions
drh9cff9dc2009-04-13 14:43:40 +00004367** using the [xFindFunction] method of the [virtual table module].
4368** But global versions of those functions
drhd68eee02009-12-11 03:44:18 +00004369** must exist in order to be overloaded.)
drhb7481e72006-09-16 21:45:14 +00004370**
drhd68eee02009-12-11 03:44:18 +00004371** ^(This API makes sure a global version of a function with a particular
drhb7481e72006-09-16 21:45:14 +00004372** name and number of parameters exists. If no such function exists
drhd68eee02009-12-11 03:44:18 +00004373** before this API is called, a new function is created.)^ ^The implementation
drhb7481e72006-09-16 21:45:14 +00004374** of the new function always causes an exception to be thrown. So
4375** the new function is not good for anything by itself. Its only
shane26b34032008-05-23 17:21:09 +00004376** purpose is to be a placeholder function that can be overloaded
drh9cff9dc2009-04-13 14:43:40 +00004377** by a [virtual table].
drhb7481e72006-09-16 21:45:14 +00004378*/
shanea79c3cc2008-08-11 17:27:01 +00004379SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
drhb7481e72006-09-16 21:45:14 +00004380
4381/*
drh9eff6162006-06-12 21:59:13 +00004382** The interface to the virtual-table mechanism defined above (back up
4383** to a comment remarkably similar to this one) is currently considered
4384** to be experimental. The interface might change in incompatible ways.
4385** If this is a problem for you, do not use the interface at this time.
4386**
drh98c94802007-10-01 13:50:31 +00004387** When the virtual-table mechanism stabilizes, we will declare the
drh9eff6162006-06-12 21:59:13 +00004388** interface fixed, support it indefinitely, and remove this comment.
4389**
4390****** EXPERIMENTAL - subject to change without notice **************
4391*/
4392
danielk19778cbadb02007-05-03 16:31:26 +00004393/*
drhd68eee02009-12-11 03:44:18 +00004394** CAPI3REF: A Handle To An Open BLOB
mihailim15194222008-06-22 09:55:14 +00004395** KEYWORDS: {BLOB handle} {BLOB handles}
drh6ed48bf2007-06-14 20:57:18 +00004396**
drhb4d58ae2008-02-21 20:17:06 +00004397** An instance of this object represents an open BLOB on which
mihailim1c492652008-06-21 18:02:16 +00004398** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
drhd68eee02009-12-11 03:44:18 +00004399** ^Objects of this type are created by [sqlite3_blob_open()]
mihailim15194222008-06-22 09:55:14 +00004400** and destroyed by [sqlite3_blob_close()].
drhd68eee02009-12-11 03:44:18 +00004401** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
mihailim15194222008-06-22 09:55:14 +00004402** can be used to read or write small subsections of the BLOB.
drhd68eee02009-12-11 03:44:18 +00004403** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
danielk19778cbadb02007-05-03 16:31:26 +00004404*/
danielk1977b4e9af92007-05-01 17:49:49 +00004405typedef struct sqlite3_blob sqlite3_blob;
4406
danielk19778cbadb02007-05-03 16:31:26 +00004407/*
drh9cd29642008-07-23 00:52:55 +00004408** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230>
drh6ed48bf2007-06-14 20:57:18 +00004409**
drhd68eee02009-12-11 03:44:18 +00004410** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
drhf84ddc12008-03-24 12:51:46 +00004411** in row iRow, column zColumn, table zTable in database zDb;
mihailim15194222008-06-22 09:55:14 +00004412** in other words, the same BLOB that would be selected by:
danielk19778cbadb02007-05-03 16:31:26 +00004413**
drh6ed48bf2007-06-14 20:57:18 +00004414** <pre>
drh49c3d572008-12-15 22:51:38 +00004415** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
drhd68eee02009-12-11 03:44:18 +00004416** </pre>)^
danielk19778cbadb02007-05-03 16:31:26 +00004417**
drhd68eee02009-12-11 03:44:18 +00004418** ^If the flags parameter is non-zero, then the BLOB is opened for read
4419** and write access. ^If it is zero, the BLOB is opened for read access.
4420** ^It is not possible to open a column that is part of an index or primary
danfedd4802009-10-07 11:29:40 +00004421** key for writing. ^If [foreign key constraints] are enabled, it is
drhc4ad1e92009-10-10 14:29:30 +00004422** not possible to open a column that is part of a [child key] for writing.
danielk19778cbadb02007-05-03 16:31:26 +00004423**
drhd68eee02009-12-11 03:44:18 +00004424** ^Note that the database name is not the filename that contains
drhf84ddc12008-03-24 12:51:46 +00004425** the database but rather the symbolic name of the database that
drhd68eee02009-12-11 03:44:18 +00004426** appears after the AS keyword when the database is connected using [ATTACH].
4427** ^For the main database file, the database name is "main".
4428** ^For TEMP tables, the database name is "temp".
drhf84ddc12008-03-24 12:51:46 +00004429**
drhd68eee02009-12-11 03:44:18 +00004430** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
drhabda6112009-05-14 22:37:47 +00004431** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
drhd68eee02009-12-11 03:44:18 +00004432** to be a null pointer.)^
4433** ^This function sets the [database connection] error code and message
drhabda6112009-05-14 22:37:47 +00004434** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
drhd68eee02009-12-11 03:44:18 +00004435** functions. ^Note that the *ppBlob variable is always initialized in a
drhabda6112009-05-14 22:37:47 +00004436** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
4437** regardless of the success or failure of this routine.
mihailim15194222008-06-22 09:55:14 +00004438**
drhd68eee02009-12-11 03:44:18 +00004439** ^(If the row that a BLOB handle points to is modified by an
drh9de1b352008-06-26 15:04:57 +00004440** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
4441** then the BLOB handle is marked as "expired".
4442** This is true if any column of the row is changed, even a column
drhd68eee02009-12-11 03:44:18 +00004443** other than the one the BLOB handle is open on.)^
4444** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
drh9de1b352008-06-26 15:04:57 +00004445** a expired BLOB handle fail with an return code of [SQLITE_ABORT].
drhd68eee02009-12-11 03:44:18 +00004446** ^(Changes written into a BLOB prior to the BLOB expiring are not
drh9de1b352008-06-26 15:04:57 +00004447** rollback by the expiration of the BLOB. Such changes will eventually
drhd68eee02009-12-11 03:44:18 +00004448** commit if the transaction continues to completion.)^
drh9de1b352008-06-26 15:04:57 +00004449**
drhd68eee02009-12-11 03:44:18 +00004450** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
4451** the opened blob. ^The size of a blob may not be changed by this
drh9e42f8a2009-08-13 20:15:29 +00004452** interface. Use the [UPDATE] SQL command to change the size of a
drhabda6112009-05-14 22:37:47 +00004453** blob.
4454**
drhd68eee02009-12-11 03:44:18 +00004455** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
drhabda6112009-05-14 22:37:47 +00004456** and the built-in [zeroblob] SQL function can be used, if desired,
4457** to create an empty, zero-filled blob in which to read or write using
4458** this interface.
4459**
4460** To avoid a resource leak, every open [BLOB handle] should eventually
4461** be released by a call to [sqlite3_blob_close()].
danielk19778cbadb02007-05-03 16:31:26 +00004462*/
danielk1977b4e9af92007-05-01 17:49:49 +00004463int sqlite3_blob_open(
4464 sqlite3*,
4465 const char *zDb,
4466 const char *zTable,
4467 const char *zColumn,
drh6d2069d2007-08-14 01:58:53 +00004468 sqlite3_int64 iRow,
danielk1977b4e9af92007-05-01 17:49:49 +00004469 int flags,
4470 sqlite3_blob **ppBlob
4471);
4472
danielk19778cbadb02007-05-03 16:31:26 +00004473/*
drhd68eee02009-12-11 03:44:18 +00004474** CAPI3REF: Close A BLOB Handle
drh6ed48bf2007-06-14 20:57:18 +00004475**
drhd68eee02009-12-11 03:44:18 +00004476** ^Closes an open [BLOB handle].
drh2dd62be2007-12-04 13:22:43 +00004477**
drhd68eee02009-12-11 03:44:18 +00004478** ^Closing a BLOB shall cause the current transaction to commit
drhf5befa02007-12-06 02:42:07 +00004479** if there are no other BLOBs, no pending prepared statements, and the
mihailim15194222008-06-22 09:55:14 +00004480** database connection is in [autocommit mode].
drhd68eee02009-12-11 03:44:18 +00004481** ^If any writes were made to the BLOB, they might be held in cache
drhabda6112009-05-14 22:37:47 +00004482** until the close operation if they will fit.
mihailim15194222008-06-22 09:55:14 +00004483**
drhd68eee02009-12-11 03:44:18 +00004484** ^(Closing the BLOB often forces the changes
drh2dd62be2007-12-04 13:22:43 +00004485** out to disk and so if any I/O errors occur, they will likely occur
drhabda6112009-05-14 22:37:47 +00004486** at the time when the BLOB is closed. Any errors that occur during
drhd68eee02009-12-11 03:44:18 +00004487** closing are reported as a non-zero return value.)^
drh2dd62be2007-12-04 13:22:43 +00004488**
drhd68eee02009-12-11 03:44:18 +00004489** ^(The BLOB is closed unconditionally. Even if this routine returns
4490** an error code, the BLOB is still closed.)^
drhb4d58ae2008-02-21 20:17:06 +00004491**
drhd68eee02009-12-11 03:44:18 +00004492** ^Calling this routine with a null pointer (such as would be returned
4493** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
danielk19778cbadb02007-05-03 16:31:26 +00004494*/
danielk1977b4e9af92007-05-01 17:49:49 +00004495int sqlite3_blob_close(sqlite3_blob *);
4496
danielk19778cbadb02007-05-03 16:31:26 +00004497/*
drhd68eee02009-12-11 03:44:18 +00004498** CAPI3REF: Return The Size Of An Open BLOB
drh6ed48bf2007-06-14 20:57:18 +00004499**
drhd68eee02009-12-11 03:44:18 +00004500** ^Returns the size in bytes of the BLOB accessible via the
4501** successfully opened [BLOB handle] in its only argument. ^The
drhabda6112009-05-14 22:37:47 +00004502** incremental blob I/O routines can only read or overwriting existing
4503** blob content; they cannot change the size of a blob.
4504**
4505** This routine only works on a [BLOB handle] which has been created
4506** by a prior successful call to [sqlite3_blob_open()] and which has not
4507** been closed by [sqlite3_blob_close()]. Passing any other pointer in
4508** to this routine results in undefined and probably undesirable behavior.
danielk19778cbadb02007-05-03 16:31:26 +00004509*/
danielk1977b4e9af92007-05-01 17:49:49 +00004510int sqlite3_blob_bytes(sqlite3_blob *);
4511
drh9eff6162006-06-12 21:59:13 +00004512/*
drhd68eee02009-12-11 03:44:18 +00004513** CAPI3REF: Read Data From A BLOB Incrementally
drh6ed48bf2007-06-14 20:57:18 +00004514**
drhd68eee02009-12-11 03:44:18 +00004515** ^(This function is used to read data from an open [BLOB handle] into a
mihailim15194222008-06-22 09:55:14 +00004516** caller-supplied buffer. N bytes of data are copied into buffer Z
drhd68eee02009-12-11 03:44:18 +00004517** from the open BLOB, starting at offset iOffset.)^
danielk19778cbadb02007-05-03 16:31:26 +00004518**
drhd68eee02009-12-11 03:44:18 +00004519** ^If offset iOffset is less than N bytes from the end of the BLOB,
4520** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
mihailim15194222008-06-22 09:55:14 +00004521** less than zero, [SQLITE_ERROR] is returned and no data is read.
drhd68eee02009-12-11 03:44:18 +00004522** ^The size of the blob (and hence the maximum value of N+iOffset)
drhabda6112009-05-14 22:37:47 +00004523** can be determined using the [sqlite3_blob_bytes()] interface.
drhf5befa02007-12-06 02:42:07 +00004524**
drhd68eee02009-12-11 03:44:18 +00004525** ^An attempt to read from an expired [BLOB handle] fails with an
drh9de1b352008-06-26 15:04:57 +00004526** error code of [SQLITE_ABORT].
4527**
drhd68eee02009-12-11 03:44:18 +00004528** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
4529** Otherwise, an [error code] or an [extended error code] is returned.)^
drhb4d58ae2008-02-21 20:17:06 +00004530**
drhabda6112009-05-14 22:37:47 +00004531** This routine only works on a [BLOB handle] which has been created
4532** by a prior successful call to [sqlite3_blob_open()] and which has not
4533** been closed by [sqlite3_blob_close()]. Passing any other pointer in
4534** to this routine results in undefined and probably undesirable behavior.
4535**
4536** See also: [sqlite3_blob_write()].
danielk19778cbadb02007-05-03 16:31:26 +00004537*/
drhb4d58ae2008-02-21 20:17:06 +00004538int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
danielk19778cbadb02007-05-03 16:31:26 +00004539
4540/*
drhd68eee02009-12-11 03:44:18 +00004541** CAPI3REF: Write Data Into A BLOB Incrementally
drh6ed48bf2007-06-14 20:57:18 +00004542**
drhd68eee02009-12-11 03:44:18 +00004543** ^This function is used to write data into an open [BLOB handle] from a
4544** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
mihailim15194222008-06-22 09:55:14 +00004545** into the open BLOB, starting at offset iOffset.
danielk19778cbadb02007-05-03 16:31:26 +00004546**
drhd68eee02009-12-11 03:44:18 +00004547** ^If the [BLOB handle] passed as the first argument was not opened for
mihailim15194222008-06-22 09:55:14 +00004548** writing (the flags parameter to [sqlite3_blob_open()] was zero),
4549** this function returns [SQLITE_READONLY].
danielk19778cbadb02007-05-03 16:31:26 +00004550**
drhd68eee02009-12-11 03:44:18 +00004551** ^This function may only modify the contents of the BLOB; it is
mihailim15194222008-06-22 09:55:14 +00004552** not possible to increase the size of a BLOB using this API.
drhd68eee02009-12-11 03:44:18 +00004553** ^If offset iOffset is less than N bytes from the end of the BLOB,
4554** [SQLITE_ERROR] is returned and no data is written. ^If N is
drhf5befa02007-12-06 02:42:07 +00004555** less than zero [SQLITE_ERROR] is returned and no data is written.
drhabda6112009-05-14 22:37:47 +00004556** The size of the BLOB (and hence the maximum value of N+iOffset)
4557** can be determined using the [sqlite3_blob_bytes()] interface.
danielk19778cbadb02007-05-03 16:31:26 +00004558**
drhd68eee02009-12-11 03:44:18 +00004559** ^An attempt to write to an expired [BLOB handle] fails with an
4560** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
drh9de1b352008-06-26 15:04:57 +00004561** before the [BLOB handle] expired are not rolled back by the
4562** expiration of the handle, though of course those changes might
4563** have been overwritten by the statement that expired the BLOB handle
4564** or by other independent statements.
4565**
drhd68eee02009-12-11 03:44:18 +00004566** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
4567** Otherwise, an [error code] or an [extended error code] is returned.)^
drhb4d58ae2008-02-21 20:17:06 +00004568**
drhabda6112009-05-14 22:37:47 +00004569** This routine only works on a [BLOB handle] which has been created
4570** by a prior successful call to [sqlite3_blob_open()] and which has not
4571** been closed by [sqlite3_blob_close()]. Passing any other pointer in
4572** to this routine results in undefined and probably undesirable behavior.
4573**
4574** See also: [sqlite3_blob_read()].
danielk19778cbadb02007-05-03 16:31:26 +00004575*/
4576int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
4577
drhd84f9462007-08-15 11:28:56 +00004578/*
drhd68eee02009-12-11 03:44:18 +00004579** CAPI3REF: Virtual File System Objects
drhd84f9462007-08-15 11:28:56 +00004580**
4581** A virtual filesystem (VFS) is an [sqlite3_vfs] object
4582** that SQLite uses to interact
drhb4d58ae2008-02-21 20:17:06 +00004583** with the underlying operating system. Most SQLite builds come with a
drhd84f9462007-08-15 11:28:56 +00004584** single default VFS that is appropriate for the host computer.
4585** New VFSes can be registered and existing VFSes can be unregistered.
4586** The following interfaces are provided.
4587**
drhd68eee02009-12-11 03:44:18 +00004588** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
4589** ^Names are case sensitive.
4590** ^Names are zero-terminated UTF-8 strings.
4591** ^If there is no match, a NULL pointer is returned.
4592** ^If zVfsName is NULL then the default VFS is returned.
drhd84f9462007-08-15 11:28:56 +00004593**
drhd68eee02009-12-11 03:44:18 +00004594** ^New VFSes are registered with sqlite3_vfs_register().
4595** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
4596** ^The same VFS can be registered multiple times without injury.
4597** ^To make an existing VFS into the default VFS, register it again
drhb4d58ae2008-02-21 20:17:06 +00004598** with the makeDflt flag set. If two different VFSes with the
4599** same name are registered, the behavior is undefined. If a
drhb6f5cf32007-08-28 15:21:45 +00004600** VFS is registered with a name that is NULL or an empty string,
4601** then the behavior is undefined.
mihailim15194222008-06-22 09:55:14 +00004602**
drhd68eee02009-12-11 03:44:18 +00004603** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
4604** ^(If the default VFS is unregistered, another VFS is chosen as
4605** the default. The choice for the new VFS is arbitrary.)^
drhd84f9462007-08-15 11:28:56 +00004606*/
drhd677b3d2007-08-20 22:48:41 +00004607sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
drhd677b3d2007-08-20 22:48:41 +00004608int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
4609int sqlite3_vfs_unregister(sqlite3_vfs*);
drhd84f9462007-08-15 11:28:56 +00004610
4611/*
drhd68eee02009-12-11 03:44:18 +00004612** CAPI3REF: Mutexes
drhd84f9462007-08-15 11:28:56 +00004613**
4614** The SQLite core uses these routines for thread
danielk19774a9d1f62008-06-19 08:51:23 +00004615** synchronization. Though they are intended for internal
drhd84f9462007-08-15 11:28:56 +00004616** use by SQLite, code that links against SQLite is
4617** permitted to use any of these routines.
4618**
mihailim15194222008-06-22 09:55:14 +00004619** The SQLite source code contains multiple implementations
drh8bacf972007-08-25 16:21:29 +00004620** of these mutex routines. An appropriate implementation
drhd68eee02009-12-11 03:44:18 +00004621** is selected automatically at compile-time. ^(The following
drh8bacf972007-08-25 16:21:29 +00004622** implementations are available in the SQLite core:
drhd84f9462007-08-15 11:28:56 +00004623**
4624** <ul>
drhc7ce76a2007-08-30 14:10:30 +00004625** <li> SQLITE_MUTEX_OS2
drhd84f9462007-08-15 11:28:56 +00004626** <li> SQLITE_MUTEX_PTHREAD
drhc7ce76a2007-08-30 14:10:30 +00004627** <li> SQLITE_MUTEX_W32
drhd84f9462007-08-15 11:28:56 +00004628** <li> SQLITE_MUTEX_NOOP
drhd68eee02009-12-11 03:44:18 +00004629** </ul>)^
drhd84f9462007-08-15 11:28:56 +00004630**
drhd68eee02009-12-11 03:44:18 +00004631** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
mihailim15194222008-06-22 09:55:14 +00004632** that does no real locking and is appropriate for use in
drhd68eee02009-12-11 03:44:18 +00004633** a single-threaded application. ^The SQLITE_MUTEX_OS2,
drhc7ce76a2007-08-30 14:10:30 +00004634** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
shane26b34032008-05-23 17:21:09 +00004635** are appropriate for use on OS/2, Unix, and Windows.
mihailim15194222008-06-22 09:55:14 +00004636**
drhd68eee02009-12-11 03:44:18 +00004637** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
drh8bacf972007-08-25 16:21:29 +00004638** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
danielk19774a9d1f62008-06-19 08:51:23 +00004639** implementation is included with the library. In this case the
4640** application must supply a custom mutex implementation using the
4641** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
mihailim15194222008-06-22 09:55:14 +00004642** before calling sqlite3_initialize() or any other public sqlite3_
drhd68eee02009-12-11 03:44:18 +00004643** function that calls sqlite3_initialize().)^
drhcb041342008-06-12 00:07:29 +00004644**
drhd68eee02009-12-11 03:44:18 +00004645** ^The sqlite3_mutex_alloc() routine allocates a new
4646** mutex and returns a pointer to it. ^If it returns NULL
4647** that means that a mutex could not be allocated. ^SQLite
4648** will unwind its stack and return an error. ^(The argument
drh6bdec4a2007-08-16 19:40:16 +00004649** to sqlite3_mutex_alloc() is one of these integer constants:
4650**
4651** <ul>
4652** <li> SQLITE_MUTEX_FAST
4653** <li> SQLITE_MUTEX_RECURSIVE
4654** <li> SQLITE_MUTEX_STATIC_MASTER
4655** <li> SQLITE_MUTEX_STATIC_MEM
drh86f8c192007-08-22 00:39:19 +00004656** <li> SQLITE_MUTEX_STATIC_MEM2
drh6bdec4a2007-08-16 19:40:16 +00004657** <li> SQLITE_MUTEX_STATIC_PRNG
danielk19779f61c2f2007-08-27 17:27:49 +00004658** <li> SQLITE_MUTEX_STATIC_LRU
danielk1977dfb316d2008-03-26 18:34:43 +00004659** <li> SQLITE_MUTEX_STATIC_LRU2
drhd68eee02009-12-11 03:44:18 +00004660** </ul>)^
drh6bdec4a2007-08-16 19:40:16 +00004661**
drhd68eee02009-12-11 03:44:18 +00004662** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
4663** cause sqlite3_mutex_alloc() to create
4664** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
4665** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
drh6bdec4a2007-08-16 19:40:16 +00004666** The mutex implementation does not need to make a distinction
4667** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
drhd68eee02009-12-11 03:44:18 +00004668** not want to. ^SQLite will only request a recursive mutex in
4669** cases where it really needs one. ^If a faster non-recursive mutex
drh6bdec4a2007-08-16 19:40:16 +00004670** implementation is available on the host platform, the mutex subsystem
4671** might return such a mutex in response to SQLITE_MUTEX_FAST.
4672**
drhd68eee02009-12-11 03:44:18 +00004673** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
4674** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
4675** a pointer to a static preexisting mutex. ^Six static mutexes are
drh6bdec4a2007-08-16 19:40:16 +00004676** used by the current version of SQLite. Future versions of SQLite
4677** may add additional static mutexes. Static mutexes are for internal
4678** use by SQLite only. Applications that use SQLite mutexes should
4679** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
4680** SQLITE_MUTEX_RECURSIVE.
4681**
drhd68eee02009-12-11 03:44:18 +00004682** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
drh6bdec4a2007-08-16 19:40:16 +00004683** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
drhd68eee02009-12-11 03:44:18 +00004684** returns a different mutex on every call. ^But for the static
drh6bdec4a2007-08-16 19:40:16 +00004685** mutex types, the same mutex is returned on every call that has
mihailim04bcc002008-06-22 10:21:27 +00004686** the same type number.
drhd84f9462007-08-15 11:28:56 +00004687**
drhd68eee02009-12-11 03:44:18 +00004688** ^The sqlite3_mutex_free() routine deallocates a previously
4689** allocated dynamic mutex. ^SQLite is careful to deallocate every
4690** dynamic mutex that it allocates. The dynamic mutexes must not be in
4691** use when they are deallocated. Attempting to deallocate a static
4692** mutex results in undefined behavior. ^SQLite never deallocates
4693** a static mutex.
drhd84f9462007-08-15 11:28:56 +00004694**
drhd68eee02009-12-11 03:44:18 +00004695** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
4696** to enter a mutex. ^If another thread is already within the mutex,
drh6bdec4a2007-08-16 19:40:16 +00004697** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
drhd68eee02009-12-11 03:44:18 +00004698** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
4699** upon successful entry. ^(Mutexes created using
drhf5befa02007-12-06 02:42:07 +00004700** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
drhd68eee02009-12-11 03:44:18 +00004701** In such cases the,
drh6bdec4a2007-08-16 19:40:16 +00004702** mutex must be exited an equal number of times before another thread
drhd68eee02009-12-11 03:44:18 +00004703** can enter.)^ ^(If the same thread tries to enter any other
drhf5befa02007-12-06 02:42:07 +00004704** kind of mutex more than once, the behavior is undefined.
drhd68eee02009-12-11 03:44:18 +00004705** SQLite will never exhibit
4706** such behavior in its own use of mutexes.)^
drhd84f9462007-08-15 11:28:56 +00004707**
drhd68eee02009-12-11 03:44:18 +00004708** ^(Some systems (for example, Windows 95) do not support the operation
mihailim15194222008-06-22 09:55:14 +00004709** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
drhd68eee02009-12-11 03:44:18 +00004710** will always return SQLITE_BUSY. The SQLite core only ever uses
4711** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
drhca49cba2007-09-04 22:31:36 +00004712**
drhd68eee02009-12-11 03:44:18 +00004713** ^The sqlite3_mutex_leave() routine exits a mutex that was
4714** previously entered by the same thread. ^(The behavior
drh8bacf972007-08-25 16:21:29 +00004715** is undefined if the mutex is not currently entered by the
drhd68eee02009-12-11 03:44:18 +00004716** calling thread or is not currently allocated. SQLite will
4717** never do either.)^
drh8bacf972007-08-25 16:21:29 +00004718**
drhd68eee02009-12-11 03:44:18 +00004719** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
drh40257ff2008-06-13 18:24:27 +00004720** sqlite3_mutex_leave() is a NULL pointer, then all three routines
4721** behave as no-ops.
4722**
drh8bacf972007-08-25 16:21:29 +00004723** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
4724*/
4725sqlite3_mutex *sqlite3_mutex_alloc(int);
4726void sqlite3_mutex_free(sqlite3_mutex*);
4727void sqlite3_mutex_enter(sqlite3_mutex*);
4728int sqlite3_mutex_try(sqlite3_mutex*);
4729void sqlite3_mutex_leave(sqlite3_mutex*);
4730
drh56a40a82008-06-18 13:47:03 +00004731/*
drhd68eee02009-12-11 03:44:18 +00004732** CAPI3REF: Mutex Methods Object
drhd5a68d32008-08-04 13:44:57 +00004733** EXPERIMENTAL
drh56a40a82008-06-18 13:47:03 +00004734**
4735** An instance of this structure defines the low-level routines
danielk19774a9d1f62008-06-19 08:51:23 +00004736** used to allocate and use mutexes.
4737**
4738** Usually, the default mutex implementations provided by SQLite are
mihailim15194222008-06-22 09:55:14 +00004739** sufficient, however the user has the option of substituting a custom
4740** implementation for specialized deployments or systems for which SQLite
danielk19774a9d1f62008-06-19 08:51:23 +00004741** does not provide a suitable implementation. In this case, the user
4742** creates and populates an instance of this structure to pass
mihailim15194222008-06-22 09:55:14 +00004743** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
danielk19774a9d1f62008-06-19 08:51:23 +00004744** Additionally, an instance of this structure can be used as an
4745** output variable when querying the system for the current mutex
4746** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
4747**
drhd68eee02009-12-11 03:44:18 +00004748** ^The xMutexInit method defined by this structure is invoked as
danielk19774a9d1f62008-06-19 08:51:23 +00004749** part of system initialization by the sqlite3_initialize() function.
drhd68eee02009-12-11 03:44:18 +00004750** ^The xMutexInit routine is calle by SQLite exactly once for each
mihailim15194222008-06-22 09:55:14 +00004751** effective call to [sqlite3_initialize()].
danielk19774a9d1f62008-06-19 08:51:23 +00004752**
drhd68eee02009-12-11 03:44:18 +00004753** ^The xMutexEnd method defined by this structure is invoked as
danielk19774a9d1f62008-06-19 08:51:23 +00004754** part of system shutdown by the sqlite3_shutdown() function. The
4755** implementation of this method is expected to release all outstanding
4756** resources obtained by the mutex methods implementation, especially
drhd68eee02009-12-11 03:44:18 +00004757** those obtained by the xMutexInit method. ^The xMutexEnd()
4758** interface is invoked exactly once for each call to [sqlite3_shutdown()].
danielk19774a9d1f62008-06-19 08:51:23 +00004759**
drhd68eee02009-12-11 03:44:18 +00004760** ^(The remaining seven methods defined by this structure (xMutexAlloc,
danielk19774a9d1f62008-06-19 08:51:23 +00004761** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
4762** xMutexNotheld) implement the following interfaces (respectively):
drh56a40a82008-06-18 13:47:03 +00004763**
4764** <ul>
danielk19774a9d1f62008-06-19 08:51:23 +00004765** <li> [sqlite3_mutex_alloc()] </li>
4766** <li> [sqlite3_mutex_free()] </li>
4767** <li> [sqlite3_mutex_enter()] </li>
4768** <li> [sqlite3_mutex_try()] </li>
4769** <li> [sqlite3_mutex_leave()] </li>
4770** <li> [sqlite3_mutex_held()] </li>
4771** <li> [sqlite3_mutex_notheld()] </li>
drhd68eee02009-12-11 03:44:18 +00004772** </ul>)^
danielk19774a9d1f62008-06-19 08:51:23 +00004773**
4774** The only difference is that the public sqlite3_XXX functions enumerated
4775** above silently ignore any invocations that pass a NULL pointer instead
4776** of a valid mutex handle. The implementations of the methods defined
4777** by this structure are not required to handle this case, the results
4778** of passing a NULL pointer instead of a valid mutex handle are undefined
4779** (i.e. it is acceptable to provide an implementation that segfaults if
4780** it is passed a NULL pointer).
drh9ac06502009-08-17 13:42:29 +00004781**
drhd68eee02009-12-11 03:44:18 +00004782** The xMutexInit() method must be threadsafe. ^It must be harmless to
drh9ac06502009-08-17 13:42:29 +00004783** invoke xMutexInit() mutiple times within the same process and without
4784** intervening calls to xMutexEnd(). Second and subsequent calls to
4785** xMutexInit() must be no-ops.
4786**
drhd68eee02009-12-11 03:44:18 +00004787** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
4788** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
4789** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
drh9ac06502009-08-17 13:42:29 +00004790** memory allocation for a fast or recursive mutex.
4791**
drhd68eee02009-12-11 03:44:18 +00004792** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
drh9ac06502009-08-17 13:42:29 +00004793** called, but only if the prior call to xMutexInit returned SQLITE_OK.
4794** If xMutexInit fails in any way, it is expected to clean up after itself
4795** prior to returning.
drh56a40a82008-06-18 13:47:03 +00004796*/
danielk19776d2ab0e2008-06-17 17:21:18 +00004797typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
4798struct sqlite3_mutex_methods {
4799 int (*xMutexInit)(void);
danielk19774a9d1f62008-06-19 08:51:23 +00004800 int (*xMutexEnd)(void);
danielk19776d2ab0e2008-06-17 17:21:18 +00004801 sqlite3_mutex *(*xMutexAlloc)(int);
4802 void (*xMutexFree)(sqlite3_mutex *);
4803 void (*xMutexEnter)(sqlite3_mutex *);
4804 int (*xMutexTry)(sqlite3_mutex *);
4805 void (*xMutexLeave)(sqlite3_mutex *);
danielk19776d2ab0e2008-06-17 17:21:18 +00004806 int (*xMutexHeld)(sqlite3_mutex *);
4807 int (*xMutexNotheld)(sqlite3_mutex *);
4808};
4809
drh8bacf972007-08-25 16:21:29 +00004810/*
drhd68eee02009-12-11 03:44:18 +00004811** CAPI3REF: Mutex Verification Routines
drhd677b3d2007-08-20 22:48:41 +00004812**
4813** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
drhd68eee02009-12-11 03:44:18 +00004814** are intended for use inside assert() statements. ^The SQLite core
drhf77a2ff2007-08-25 14:49:36 +00004815** never uses these routines except inside an assert() and applications
drhd68eee02009-12-11 03:44:18 +00004816** are advised to follow the lead of the core. ^The SQLite core only
drh8bacf972007-08-25 16:21:29 +00004817** provides implementations for these routines when it is compiled
drhd68eee02009-12-11 03:44:18 +00004818** with the SQLITE_DEBUG flag. ^External mutex implementations
drh8bacf972007-08-25 16:21:29 +00004819** are only required to provide these routines if SQLITE_DEBUG is
4820** defined and if NDEBUG is not defined.
4821**
drhd68eee02009-12-11 03:44:18 +00004822** ^These routines should return true if the mutex in their argument
mihailim04bcc002008-06-22 10:21:27 +00004823** is held or not held, respectively, by the calling thread.
drh8bacf972007-08-25 16:21:29 +00004824**
drhd68eee02009-12-11 03:44:18 +00004825** ^The implementation is not required to provided versions of these
mihailim04bcc002008-06-22 10:21:27 +00004826** routines that actually work. If the implementation does not provide working
4827** versions of these routines, it should at least provide stubs that always
4828** return true so that one does not get spurious assertion failures.
drhd677b3d2007-08-20 22:48:41 +00004829**
drhd68eee02009-12-11 03:44:18 +00004830** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
4831** the routine should return 1. This seems counter-intuitive since
drhd677b3d2007-08-20 22:48:41 +00004832** clearly the mutex cannot be held if it does not exist. But the
4833** the reason the mutex does not exist is because the build is not
4834** using mutexes. And we do not want the assert() containing the
4835** call to sqlite3_mutex_held() to fail, so a non-zero return is
drhd68eee02009-12-11 03:44:18 +00004836** the appropriate thing to do. ^The sqlite3_mutex_notheld()
drhd677b3d2007-08-20 22:48:41 +00004837** interface should also return 1 when given a NULL pointer.
drhd84f9462007-08-15 11:28:56 +00004838*/
drh0edb3cf2009-12-10 01:17:29 +00004839#ifndef NDEBUG
drhd677b3d2007-08-20 22:48:41 +00004840int sqlite3_mutex_held(sqlite3_mutex*);
4841int sqlite3_mutex_notheld(sqlite3_mutex*);
drh0edb3cf2009-12-10 01:17:29 +00004842#endif
drh32bc3f62007-08-21 20:25:39 +00004843
4844/*
drhd68eee02009-12-11 03:44:18 +00004845** CAPI3REF: Mutex Types
drh32bc3f62007-08-21 20:25:39 +00004846**
drhd5a68d32008-08-04 13:44:57 +00004847** The [sqlite3_mutex_alloc()] interface takes a single argument
mihailim04bcc002008-06-22 10:21:27 +00004848** which is one of these integer constants.
drhd5a68d32008-08-04 13:44:57 +00004849**
4850** The set of static mutexes may change from one SQLite release to the
4851** next. Applications that override the built-in mutex logic must be
4852** prepared to accommodate additional static mutexes.
drh32bc3f62007-08-21 20:25:39 +00004853*/
drh6bdec4a2007-08-16 19:40:16 +00004854#define SQLITE_MUTEX_FAST 0
4855#define SQLITE_MUTEX_RECURSIVE 1
4856#define SQLITE_MUTEX_STATIC_MASTER 2
drh86f8c192007-08-22 00:39:19 +00004857#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
drh7555d8e2009-03-20 13:15:30 +00004858#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
4859#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
drh86f8c192007-08-22 00:39:19 +00004860#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
danielk19779f61c2f2007-08-27 17:27:49 +00004861#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
danielk1977dfb316d2008-03-26 18:34:43 +00004862#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */
drh6d2069d2007-08-14 01:58:53 +00004863
drhcc6bb3e2007-08-31 16:11:35 +00004864/*
drhd68eee02009-12-11 03:44:18 +00004865** CAPI3REF: Retrieve the mutex for a database connection
drh4413d0e2008-11-04 13:46:27 +00004866**
drhd68eee02009-12-11 03:44:18 +00004867** ^This interface returns a pointer the [sqlite3_mutex] object that
drh4413d0e2008-11-04 13:46:27 +00004868** serializes access to the [database connection] given in the argument
4869** when the [threading mode] is Serialized.
drhd68eee02009-12-11 03:44:18 +00004870** ^If the [threading mode] is Single-thread or Multi-thread then this
drh4413d0e2008-11-04 13:46:27 +00004871** routine returns a NULL pointer.
4872*/
4873sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
4874
4875/*
drh9cd29642008-07-23 00:52:55 +00004876** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800>
drhcc6bb3e2007-08-31 16:11:35 +00004877**
drhd68eee02009-12-11 03:44:18 +00004878** ^The [sqlite3_file_control()] interface makes a direct call to the
drhcc6bb3e2007-08-31 16:11:35 +00004879** xFileControl method for the [sqlite3_io_methods] object associated
drhd68eee02009-12-11 03:44:18 +00004880** with a particular database identified by the second argument. ^The
4881** name of the database "main" for the main database or "temp" for the
4882** TEMP database, or the name that appears after the AS keyword for
4883** databases that are added using the [ATTACH] SQL command.
4884** ^A NULL pointer can be used in place of "main" to refer to the
4885** main database file.
4886** ^The third and fourth parameters to this routine
drhcc6bb3e2007-08-31 16:11:35 +00004887** are passed directly through to the second and third parameters of
drhd68eee02009-12-11 03:44:18 +00004888** the xFileControl method. ^The return value of the xFileControl
drhcc6bb3e2007-08-31 16:11:35 +00004889** method becomes the return value of this routine.
4890**
drhd68eee02009-12-11 03:44:18 +00004891** ^If the second parameter (zDbName) does not match the name of any
4892** open database file, then SQLITE_ERROR is returned. ^This error
drhcc6bb3e2007-08-31 16:11:35 +00004893** code is not remembered and will not be recalled by [sqlite3_errcode()]
drhd68eee02009-12-11 03:44:18 +00004894** or [sqlite3_errmsg()]. The underlying xFileControl method might
4895** also return SQLITE_ERROR. There is no way to distinguish between
drhcc6bb3e2007-08-31 16:11:35 +00004896** an incorrect zDbName and an SQLITE_ERROR return from the underlying
drhd68eee02009-12-11 03:44:18 +00004897** xFileControl method.
drh4ff7fa02007-09-01 18:17:21 +00004898**
4899** See also: [SQLITE_FCNTL_LOCKSTATE]
drhcc6bb3e2007-08-31 16:11:35 +00004900*/
4901int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
drh6d2069d2007-08-14 01:58:53 +00004902
danielk19778cbadb02007-05-03 16:31:26 +00004903/*
drhd68eee02009-12-11 03:44:18 +00004904** CAPI3REF: Testing Interface
drhed13d982008-01-31 14:43:24 +00004905**
drhd68eee02009-12-11 03:44:18 +00004906** ^The sqlite3_test_control() interface is used to read out internal
drhed13d982008-01-31 14:43:24 +00004907** state of SQLite and to inject faults into SQLite for testing
drhd68eee02009-12-11 03:44:18 +00004908** purposes. ^The first parameter is an operation code that determines
drhed13d982008-01-31 14:43:24 +00004909** the number, meaning, and operation of all subsequent parameters.
4910**
4911** This interface is not for use by applications. It exists solely
4912** for verifying the correct operation of the SQLite library. Depending
4913** on how the SQLite library is compiled, this interface might not exist.
4914**
4915** The details of the operation codes, their meanings, the parameters
4916** they take, and what they do are all subject to change without notice.
4917** Unlike most of the SQLite API, this function is not guaranteed to
4918** operate consistently from one release to the next.
4919*/
4920int sqlite3_test_control(int op, ...);
4921
4922/*
drhd68eee02009-12-11 03:44:18 +00004923** CAPI3REF: Testing Interface Operation Codes
drhed13d982008-01-31 14:43:24 +00004924**
4925** These constants are the valid operation code parameters used
4926** as the first argument to [sqlite3_test_control()].
4927**
shane26b34032008-05-23 17:21:09 +00004928** These parameters and their meanings are subject to change
drhed13d982008-01-31 14:43:24 +00004929** without notice. These values are for testing purposes only.
4930** Applications should not use any of these parameters or the
4931** [sqlite3_test_control()] interface.
4932*/
drh2fa18682008-03-19 14:15:34 +00004933#define SQLITE_TESTCTRL_PRNG_SAVE 5
4934#define SQLITE_TESTCTRL_PRNG_RESTORE 6
4935#define SQLITE_TESTCTRL_PRNG_RESET 7
drh3088d592008-03-21 16:45:47 +00004936#define SQLITE_TESTCTRL_BITVEC_TEST 8
danielk1977d09414c2008-06-19 18:17:49 +00004937#define SQLITE_TESTCTRL_FAULT_INSTALL 9
danielk19772d1d86f2008-06-20 14:59:51 +00004938#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
drhc7a3bb92009-02-05 16:31:45 +00004939#define SQLITE_TESTCTRL_PENDING_BYTE 11
drhf3af63f2009-05-09 18:59:42 +00004940#define SQLITE_TESTCTRL_ASSERT 12
4941#define SQLITE_TESTCTRL_ALWAYS 13
drhc046e3e2009-07-15 11:26:44 +00004942#define SQLITE_TESTCTRL_RESERVE 14
drhed13d982008-01-31 14:43:24 +00004943
drhf7141992008-06-19 00:16:08 +00004944/*
drhd68eee02009-12-11 03:44:18 +00004945** CAPI3REF: SQLite Runtime Status
drhd5a68d32008-08-04 13:44:57 +00004946** EXPERIMENTAL
drhf7141992008-06-19 00:16:08 +00004947**
drhd68eee02009-12-11 03:44:18 +00004948** ^This interface is used to retrieve runtime status information
drhf7141992008-06-19 00:16:08 +00004949** about the preformance of SQLite, and optionally to reset various
drhd68eee02009-12-11 03:44:18 +00004950** highwater marks. ^The first argument is an integer code for
4951** the specific parameter to measure. ^Recognized integer codes
drhf7141992008-06-19 00:16:08 +00004952** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].
drhd68eee02009-12-11 03:44:18 +00004953** ^The current value of the parameter is returned into *pCurrent.
4954** ^The highest recorded value is returned in *pHighwater. ^If the
drhf7141992008-06-19 00:16:08 +00004955** resetFlag is true, then the highest record value is reset after
drhd68eee02009-12-11 03:44:18 +00004956** *pHighwater is written. ^(Some parameters do not record the highest
drhf7141992008-06-19 00:16:08 +00004957** value. For those parameters
drhd68eee02009-12-11 03:44:18 +00004958** nothing is written into *pHighwater and the resetFlag is ignored.)^
4959** ^(Other parameters record only the highwater mark and not the current
4960** value. For these latter parameters nothing is written into *pCurrent.)^
drhf7141992008-06-19 00:16:08 +00004961**
drhd68eee02009-12-11 03:44:18 +00004962** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
4963** non-zero [error code] on failure.
drhf7141992008-06-19 00:16:08 +00004964**
drh6aa5f152009-08-19 15:57:07 +00004965** This routine is threadsafe but is not atomic. This routine can be
drhf7141992008-06-19 00:16:08 +00004966** called while other threads are running the same or different SQLite
4967** interfaces. However the values returned in *pCurrent and
4968** *pHighwater reflect the status of SQLite at different points in time
4969** and it is possible that another thread might change the parameter
4970** in between the times when *pCurrent and *pHighwater are written.
4971**
drh2462e322008-07-31 14:47:54 +00004972** See also: [sqlite3_db_status()]
drhf7141992008-06-19 00:16:08 +00004973*/
shanea79c3cc2008-08-11 17:27:01 +00004974SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
drh2462e322008-07-31 14:47:54 +00004975
danielk1977075c23a2008-09-01 18:34:20 +00004976
drhf7141992008-06-19 00:16:08 +00004977/*
drhd68eee02009-12-11 03:44:18 +00004978** CAPI3REF: Status Parameters
drhd5a68d32008-08-04 13:44:57 +00004979** EXPERIMENTAL
drhf7141992008-06-19 00:16:08 +00004980**
4981** These integer constants designate various run-time status parameters
4982** that can be returned by [sqlite3_status()].
4983**
4984** <dl>
drhd68eee02009-12-11 03:44:18 +00004985** ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
drhf7141992008-06-19 00:16:08 +00004986** <dd>This parameter is the current amount of memory checked out
mihailim15194222008-06-22 09:55:14 +00004987** using [sqlite3_malloc()], either directly or indirectly. The
drhf7141992008-06-19 00:16:08 +00004988** figure includes calls made to [sqlite3_malloc()] by the application
4989** and internal memory usage by the SQLite library. Scratch memory
4990** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
4991** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
4992** this parameter. The amount returned is the sum of the allocation
drhd68eee02009-12-11 03:44:18 +00004993** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
drhf7141992008-06-19 00:16:08 +00004994**
drhd68eee02009-12-11 03:44:18 +00004995** ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
drhe50135e2008-08-05 17:53:22 +00004996** <dd>This parameter records the largest memory allocation request
4997** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
4998** internal equivalents). Only the value returned in the
4999** *pHighwater parameter to [sqlite3_status()] is of interest.
drhd68eee02009-12-11 03:44:18 +00005000** The value written into the *pCurrent parameter is undefined.</dd>)^
drhe50135e2008-08-05 17:53:22 +00005001**
drhd68eee02009-12-11 03:44:18 +00005002** ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
drhf7141992008-06-19 00:16:08 +00005003** <dd>This parameter returns the number of pages used out of the
drhe50135e2008-08-05 17:53:22 +00005004** [pagecache memory allocator] that was configured using
5005** [SQLITE_CONFIG_PAGECACHE]. The
drhd68eee02009-12-11 03:44:18 +00005006** value returned is in pages, not in bytes.</dd>)^
drhf7141992008-06-19 00:16:08 +00005007**
drhd68eee02009-12-11 03:44:18 +00005008** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
drhf7141992008-06-19 00:16:08 +00005009** <dd>This parameter returns the number of bytes of page cache
5010** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE]
drhe50135e2008-08-05 17:53:22 +00005011** buffer and where forced to overflow to [sqlite3_malloc()]. The
5012** returned value includes allocations that overflowed because they
5013** where too large (they were larger than the "sz" parameter to
5014** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
drhd68eee02009-12-11 03:44:18 +00005015** no space was left in the page cache.</dd>)^
drhe50135e2008-08-05 17:53:22 +00005016**
drhd68eee02009-12-11 03:44:18 +00005017** ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
drhe50135e2008-08-05 17:53:22 +00005018** <dd>This parameter records the largest memory allocation request
5019** handed to [pagecache memory allocator]. Only the value returned in the
5020** *pHighwater parameter to [sqlite3_status()] is of interest.
drhd68eee02009-12-11 03:44:18 +00005021** The value written into the *pCurrent parameter is undefined.</dd>)^
drhf7141992008-06-19 00:16:08 +00005022**
drhd68eee02009-12-11 03:44:18 +00005023** ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
drhf7141992008-06-19 00:16:08 +00005024** <dd>This parameter returns the number of allocations used out of the
drhe50135e2008-08-05 17:53:22 +00005025** [scratch memory allocator] configured using
drhf7141992008-06-19 00:16:08 +00005026** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
drhe50135e2008-08-05 17:53:22 +00005027** in bytes. Since a single thread may only have one scratch allocation
drhf7141992008-06-19 00:16:08 +00005028** outstanding at time, this parameter also reports the number of threads
drhd68eee02009-12-11 03:44:18 +00005029** using scratch memory at the same time.</dd>)^
drhf7141992008-06-19 00:16:08 +00005030**
drhd68eee02009-12-11 03:44:18 +00005031** ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
drhf7141992008-06-19 00:16:08 +00005032** <dd>This parameter returns the number of bytes of scratch memory
5033** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH]
drhe50135e2008-08-05 17:53:22 +00005034** buffer and where forced to overflow to [sqlite3_malloc()]. The values
5035** returned include overflows because the requested allocation was too
5036** larger (that is, because the requested allocation was larger than the
5037** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
5038** slots were available.
drhd68eee02009-12-11 03:44:18 +00005039** </dd>)^
drhf7141992008-06-19 00:16:08 +00005040**
drhd68eee02009-12-11 03:44:18 +00005041** ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
drhf7141992008-06-19 00:16:08 +00005042** <dd>This parameter records the largest memory allocation request
drhe50135e2008-08-05 17:53:22 +00005043** handed to [scratch memory allocator]. Only the value returned in the
5044** *pHighwater parameter to [sqlite3_status()] is of interest.
drhd68eee02009-12-11 03:44:18 +00005045** The value written into the *pCurrent parameter is undefined.</dd>)^
drhec424a52008-07-25 15:39:03 +00005046**
drhd68eee02009-12-11 03:44:18 +00005047** ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
drhec424a52008-07-25 15:39:03 +00005048** <dd>This parameter records the deepest parser stack. It is only
drhd68eee02009-12-11 03:44:18 +00005049** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
drhf7141992008-06-19 00:16:08 +00005050** </dl>
5051**
5052** New status parameters may be added from time to time.
5053*/
5054#define SQLITE_STATUS_MEMORY_USED 0
5055#define SQLITE_STATUS_PAGECACHE_USED 1
5056#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
5057#define SQLITE_STATUS_SCRATCH_USED 3
5058#define SQLITE_STATUS_SCRATCH_OVERFLOW 4
5059#define SQLITE_STATUS_MALLOC_SIZE 5
drhec424a52008-07-25 15:39:03 +00005060#define SQLITE_STATUS_PARSER_STACK 6
drhe50135e2008-08-05 17:53:22 +00005061#define SQLITE_STATUS_PAGECACHE_SIZE 7
5062#define SQLITE_STATUS_SCRATCH_SIZE 8
drhf7141992008-06-19 00:16:08 +00005063
drh633e6d52008-07-28 19:34:53 +00005064/*
drhd68eee02009-12-11 03:44:18 +00005065** CAPI3REF: Database Connection Status
drhd1d38482008-10-07 23:46:38 +00005066** EXPERIMENTAL
5067**
drhd68eee02009-12-11 03:44:18 +00005068** ^This interface is used to retrieve runtime status information
5069** about a single [database connection]. ^The first argument is the
5070** database connection object to be interrogated. ^The second argument
5071** is the parameter to interrogate. ^Currently, the only allowed value
drhd1d38482008-10-07 23:46:38 +00005072** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].
5073** Additional options will likely appear in future releases of SQLite.
5074**
drhd68eee02009-12-11 03:44:18 +00005075** ^The current value of the requested parameter is written into *pCur
5076** and the highest instantaneous value is written into *pHiwtr. ^If
drhd1d38482008-10-07 23:46:38 +00005077** the resetFlg is true, then the highest instantaneous value is
5078** reset back down to the current value.
5079**
5080** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
5081*/
5082SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
5083
5084/*
drhd68eee02009-12-11 03:44:18 +00005085** CAPI3REF: Status Parameters for database connections
drhd5a68d32008-08-04 13:44:57 +00005086** EXPERIMENTAL
drh633e6d52008-07-28 19:34:53 +00005087**
drh6aa5f152009-08-19 15:57:07 +00005088** These constants are the available integer "verbs" that can be passed as
5089** the second argument to the [sqlite3_db_status()] interface.
5090**
5091** New verbs may be added in future releases of SQLite. Existing verbs
5092** might be discontinued. Applications should check the return code from
5093** [sqlite3_db_status()] to make sure that the call worked.
5094** The [sqlite3_db_status()] interface will return a non-zero error code
5095** if a discontinued or unsupported verb is invoked.
drh633e6d52008-07-28 19:34:53 +00005096**
5097** <dl>
drhd68eee02009-12-11 03:44:18 +00005098** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
drh633e6d52008-07-28 19:34:53 +00005099** <dd>This parameter returns the number of lookaside memory slots currently
drhd68eee02009-12-11 03:44:18 +00005100** checked out.</dd>)^
drh633e6d52008-07-28 19:34:53 +00005101** </dl>
5102*/
5103#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
drhed13d982008-01-31 14:43:24 +00005104
drhd1d38482008-10-07 23:46:38 +00005105
5106/*
drhd68eee02009-12-11 03:44:18 +00005107** CAPI3REF: Prepared Statement Status
drhd1d38482008-10-07 23:46:38 +00005108** EXPERIMENTAL
5109**
drhd68eee02009-12-11 03:44:18 +00005110** ^(Each prepared statement maintains various
drhd1d38482008-10-07 23:46:38 +00005111** [SQLITE_STMTSTATUS_SORT | counters] that measure the number
drhd68eee02009-12-11 03:44:18 +00005112** of times it has performed specific operations.) These counters can
drhd1d38482008-10-07 23:46:38 +00005113** be used to monitor the performance characteristics of the prepared
5114** statements. For example, if the number of table steps greatly exceeds
5115** the number of table searches or result rows, that would tend to indicate
5116** that the prepared statement is using a full table scan rather than
5117** an index.
5118**
drhd68eee02009-12-11 03:44:18 +00005119** ^(This interface is used to retrieve and reset counter values from
drhd1d38482008-10-07 23:46:38 +00005120** a [prepared statement]. The first argument is the prepared statement
5121** object to be interrogated. The second argument
5122** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter]
drhd68eee02009-12-11 03:44:18 +00005123** to be interrogated.)^
5124** ^The current value of the requested counter is returned.
5125** ^If the resetFlg is true, then the counter is reset to zero after this
drhd1d38482008-10-07 23:46:38 +00005126** interface call returns.
5127**
5128** See also: [sqlite3_status()] and [sqlite3_db_status()].
5129*/
5130SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
5131
5132/*
drhd68eee02009-12-11 03:44:18 +00005133** CAPI3REF: Status Parameters for prepared statements
drhd1d38482008-10-07 23:46:38 +00005134** EXPERIMENTAL
5135**
5136** These preprocessor macros define integer codes that name counter
5137** values associated with the [sqlite3_stmt_status()] interface.
5138** The meanings of the various counters are as follows:
5139**
5140** <dl>
5141** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
drhd68eee02009-12-11 03:44:18 +00005142** <dd>^This is the number of times that SQLite has stepped forward in
drhd1d38482008-10-07 23:46:38 +00005143** a table as part of a full table scan. Large numbers for this counter
5144** may indicate opportunities for performance improvement through
5145** careful use of indices.</dd>
5146**
5147** <dt>SQLITE_STMTSTATUS_SORT</dt>
drhd68eee02009-12-11 03:44:18 +00005148** <dd>^This is the number of sort operations that have occurred.
drhd1d38482008-10-07 23:46:38 +00005149** A non-zero value in this counter may indicate an opportunity to
5150** improvement performance through careful use of indices.</dd>
5151**
5152** </dl>
5153*/
5154#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
5155#define SQLITE_STMTSTATUS_SORT 2
5156
drhed13d982008-01-31 14:43:24 +00005157/*
drh21614742008-11-18 19:18:08 +00005158** CAPI3REF: Custom Page Cache Object
5159** EXPERIMENTAL
5160**
danielk1977bc2ca9e2008-11-13 14:28:28 +00005161** The sqlite3_pcache type is opaque. It is implemented by
5162** the pluggable module. The SQLite core has no knowledge of
5163** its size or internal structure and never deals with the
5164** sqlite3_pcache object except by holding and passing pointers
5165** to the object.
drh21614742008-11-18 19:18:08 +00005166**
5167** See [sqlite3_pcache_methods] for additional information.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005168*/
5169typedef struct sqlite3_pcache sqlite3_pcache;
5170
5171/*
drh21614742008-11-18 19:18:08 +00005172** CAPI3REF: Application Defined Page Cache.
drh67fba282009-08-26 00:26:51 +00005173** KEYWORDS: {page cache}
danielk1977bc2ca9e2008-11-13 14:28:28 +00005174** EXPERIMENTAL
5175**
drhd68eee02009-12-11 03:44:18 +00005176** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
danielk1977bc2ca9e2008-11-13 14:28:28 +00005177** register an alternative page cache implementation by passing in an
drhd68eee02009-12-11 03:44:18 +00005178** instance of the sqlite3_pcache_methods structure.) The majority of the
shane7c7c3112009-08-17 15:31:23 +00005179** heap memory used by SQLite is used by the page cache to cache data read
danielk1977bc2ca9e2008-11-13 14:28:28 +00005180** from, or ready to be written to, the database file. By implementing a
5181** custom page cache using this API, an application can control more
shane7c7c3112009-08-17 15:31:23 +00005182** precisely the amount of memory consumed by SQLite, the way in which
drh67fba282009-08-26 00:26:51 +00005183** that memory is allocated and released, and the policies used to
danielk1977bc2ca9e2008-11-13 14:28:28 +00005184** determine exactly which parts of a database file are cached and for
5185** how long.
5186**
drhd68eee02009-12-11 03:44:18 +00005187** ^(The contents of the sqlite3_pcache_methods structure are copied to an
drh67fba282009-08-26 00:26:51 +00005188** internal buffer by SQLite within the call to [sqlite3_config]. Hence
5189** the application may discard the parameter after the call to
drhd68eee02009-12-11 03:44:18 +00005190** [sqlite3_config()] returns.)^
danielk1977bc2ca9e2008-11-13 14:28:28 +00005191**
drhd68eee02009-12-11 03:44:18 +00005192** ^The xInit() method is called once for each call to [sqlite3_initialize()]
5193** (usually only once during the lifetime of the process). ^It is passed
5194** a copy of the sqlite3_pcache_methods.pArg value. ^It can be used to set
danielk1977bc2ca9e2008-11-13 14:28:28 +00005195** up global structures and mutexes required by the custom page cache
shane7c7c3112009-08-17 15:31:23 +00005196** implementation.
5197**
drhd68eee02009-12-11 03:44:18 +00005198** ^The xShutdown() method is called from within [sqlite3_shutdown()],
shane7c7c3112009-08-17 15:31:23 +00005199** if the application invokes this API. It can be used to clean up
5200** any outstanding resources before process shutdown, if required.
5201**
drhd68eee02009-12-11 03:44:18 +00005202** ^SQLite holds a [SQLITE_MUTEX_RECURSIVE] mutex when it invokes
5203** the xInit method, so the xInit method need not be threadsafe. ^The
shane7c7c3112009-08-17 15:31:23 +00005204** xShutdown method is only called from [sqlite3_shutdown()] so it does
5205** not need to be threadsafe either. All other methods must be threadsafe
5206** in multithreaded applications.
5207**
drhd68eee02009-12-11 03:44:18 +00005208** ^SQLite will never invoke xInit() more than once without an intervening
shane7c7c3112009-08-17 15:31:23 +00005209** call to xShutdown().
danielk1977bc2ca9e2008-11-13 14:28:28 +00005210**
drhd68eee02009-12-11 03:44:18 +00005211** ^The xCreate() method is used to construct a new cache instance. SQLite
drh67fba282009-08-26 00:26:51 +00005212** will typically create one cache instance for each open database file,
drhd68eee02009-12-11 03:44:18 +00005213** though this is not guaranteed. ^The
danielk1977bc2ca9e2008-11-13 14:28:28 +00005214** first parameter, szPage, is the size in bytes of the pages that must
drhd68eee02009-12-11 03:44:18 +00005215** be allocated by the cache. ^szPage will not be a power of two. ^szPage
drh67fba282009-08-26 00:26:51 +00005216** will the page size of the database file that is to be cached plus an
drhd68eee02009-12-11 03:44:18 +00005217** increment (here called "R") of about 100 or 200. ^SQLite will use the
drh67fba282009-08-26 00:26:51 +00005218** extra R bytes on each page to store metadata about the underlying
5219** database page on disk. The value of R depends
5220** on the SQLite version, the target platform, and how SQLite was compiled.
drhd68eee02009-12-11 03:44:18 +00005221** ^R is constant for a particular build of SQLite. ^The second argument to
drh67fba282009-08-26 00:26:51 +00005222** xCreate(), bPurgeable, is true if the cache being created will
5223** be used to cache database pages of a file stored on disk, or
drhd68eee02009-12-11 03:44:18 +00005224** false if it is used for an in-memory database. ^The cache implementation
drh67fba282009-08-26 00:26:51 +00005225** does not have to do anything special based with the value of bPurgeable;
drhd68eee02009-12-11 03:44:18 +00005226** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
drh67fba282009-08-26 00:26:51 +00005227** never invoke xUnpin() except to deliberately delete a page.
drhd68eee02009-12-11 03:44:18 +00005228** ^In other words, a cache created with bPurgeable set to false will
drh67fba282009-08-26 00:26:51 +00005229** never contain any unpinned pages.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005230**
drhd68eee02009-12-11 03:44:18 +00005231** ^(The xCachesize() method may be called at any time by SQLite to set the
danielk1977bc2ca9e2008-11-13 14:28:28 +00005232** suggested maximum cache-size (number of pages stored by) the cache
5233** instance passed as the first argument. This is the value configured using
drhd68eee02009-12-11 03:44:18 +00005234** the SQLite "[PRAGMA cache_size]" command.) ^As with the bPurgeable parameter,
drh67fba282009-08-26 00:26:51 +00005235** the implementation is not required to do anything with this
5236** value; it is advisory only.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005237**
drhd68eee02009-12-11 03:44:18 +00005238** ^The xPagecount() method should return the number of pages currently
drh67fba282009-08-26 00:26:51 +00005239** stored in the cache.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005240**
drhd68eee02009-12-11 03:44:18 +00005241** T^he xFetch() method is used to fetch a page and return a pointer to it.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005242** A 'page', in this context, is a buffer of szPage bytes aligned at an
drhd68eee02009-12-11 03:44:18 +00005243** 8-byte boundary. The page to be fetched is determined by the key. ^The
danielk1977bc2ca9e2008-11-13 14:28:28 +00005244** mimimum key value is 1. After it has been retrieved using xFetch, the page
drh67fba282009-08-26 00:26:51 +00005245** is considered to be "pinned".
danielk1977bc2ca9e2008-11-13 14:28:28 +00005246**
drhd68eee02009-12-11 03:44:18 +00005247** ^If the requested page is already in the page cache, then the page cache
drh67fba282009-08-26 00:26:51 +00005248** implementation must return a pointer to the page buffer with its content
drhd68eee02009-12-11 03:44:18 +00005249** intact. ^(If the requested page is not already in the cache, then the
drh67fba282009-08-26 00:26:51 +00005250** behavior of the cache implementation is determined by the value of the
5251** createFlag parameter passed to xFetch, according to the following table:
danielk1977bc2ca9e2008-11-13 14:28:28 +00005252**
5253** <table border=1 width=85% align=center>
drh67fba282009-08-26 00:26:51 +00005254** <tr><th> createFlag <th> Behaviour when page is not already in cache
5255** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
5256** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
5257** Otherwise return NULL.
5258** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
5259** NULL if allocating a new page is effectively impossible.
drhd68eee02009-12-11 03:44:18 +00005260** </table>)^
danielk1977bc2ca9e2008-11-13 14:28:28 +00005261**
drh67fba282009-08-26 00:26:51 +00005262** SQLite will normally invoke xFetch() with a createFlag of 0 or 1. If
5263** a call to xFetch() with createFlag==1 returns NULL, then SQLite will
5264** attempt to unpin one or more cache pages by spilling the content of
5265** pinned pages to disk and synching the operating system disk cache. After
5266** attempting to unpin pages, the xFetch() method will be invoked again with
5267** a createFlag of 2.
5268**
drhd68eee02009-12-11 03:44:18 +00005269** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
5270** as its second argument. ^(If the third parameter, discard, is non-zero,
danielk1977bc2ca9e2008-11-13 14:28:28 +00005271** then the page should be evicted from the cache. In this case SQLite
5272** assumes that the next time the page is retrieved from the cache using
drhd68eee02009-12-11 03:44:18 +00005273** the xFetch() method, it will be zeroed.)^ ^If the discard parameter is
5274** zero, then the page is considered to be unpinned. ^The cache implementation
drh67fba282009-08-26 00:26:51 +00005275** may choose to evict unpinned pages at any time.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005276**
drhd68eee02009-12-11 03:44:18 +00005277** ^(The cache is not required to perform any reference counting. A single
danielk1977bc2ca9e2008-11-13 14:28:28 +00005278** call to xUnpin() unpins the page regardless of the number of prior calls
drhd68eee02009-12-11 03:44:18 +00005279** to xFetch().)^
danielk1977bc2ca9e2008-11-13 14:28:28 +00005280**
drhd68eee02009-12-11 03:44:18 +00005281** ^The xRekey() method is used to change the key value associated with the
5282** page passed as the second argument from oldKey to newKey. ^If the cache
drhb232c232008-11-19 01:20:26 +00005283** previously contains an entry associated with newKey, it should be
drhd68eee02009-12-11 03:44:18 +00005284** discarded. ^Any prior cache entry associated with newKey is guaranteed not
drhb232c232008-11-19 01:20:26 +00005285** to be pinned.
danielk1977bc2ca9e2008-11-13 14:28:28 +00005286**
drhd68eee02009-12-11 03:44:18 +00005287** ^When SQLite calls the xTruncate() method, the cache must discard all
danielk1977bc2ca9e2008-11-13 14:28:28 +00005288** existing cache entries with page numbers (keys) greater than or equal
drhd68eee02009-12-11 03:44:18 +00005289** to the value of the iLimit parameter passed to xTruncate(). ^If any
danielk1977bc2ca9e2008-11-13 14:28:28 +00005290** of these pages are pinned, they are implicitly unpinned, meaning that
5291** they can be safely discarded.
5292**
drhd68eee02009-12-11 03:44:18 +00005293** ^The xDestroy() method is used to delete a cache allocated by xCreate().
5294** All resources associated with the specified cache should be freed. ^After
drh21614742008-11-18 19:18:08 +00005295** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
danielk1977bc2ca9e2008-11-13 14:28:28 +00005296** handle invalid, and will not use it with any other sqlite3_pcache_methods
5297** functions.
5298*/
5299typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
5300struct sqlite3_pcache_methods {
5301 void *pArg;
5302 int (*xInit)(void*);
5303 void (*xShutdown)(void*);
5304 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
5305 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
5306 int (*xPagecount)(sqlite3_pcache*);
5307 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
5308 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
5309 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
5310 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
5311 void (*xDestroy)(sqlite3_pcache*);
5312};
5313
5314/*
drh27b3b842009-02-03 18:25:13 +00005315** CAPI3REF: Online Backup Object
5316** EXPERIMENTAL
5317**
5318** The sqlite3_backup object records state information about an ongoing
drhd68eee02009-12-11 03:44:18 +00005319** online backup operation. ^The sqlite3_backup object is created by
drh27b3b842009-02-03 18:25:13 +00005320** a call to [sqlite3_backup_init()] and is destroyed by a call to
5321** [sqlite3_backup_finish()].
drh52224a72009-02-10 13:41:42 +00005322**
5323** See Also: [Using the SQLite Online Backup API]
drh27b3b842009-02-03 18:25:13 +00005324*/
5325typedef struct sqlite3_backup sqlite3_backup;
5326
5327/*
danielk197704103022009-02-03 16:51:24 +00005328** CAPI3REF: Online Backup API.
5329** EXPERIMENTAL
5330**
drhd68eee02009-12-11 03:44:18 +00005331** The backup API copies the content of one database into another.
5332** It is useful either for creating backups of databases or
danielk197704103022009-02-03 16:51:24 +00005333** for copying in-memory databases to or from persistent files.
5334**
drh52224a72009-02-10 13:41:42 +00005335** See Also: [Using the SQLite Online Backup API]
5336**
drhd68eee02009-12-11 03:44:18 +00005337** ^Exclusive access is required to the destination database for the
5338** duration of the operation. ^However the source database is only
5339** read-locked while it is actually being read; it is not locked
5340** continuously for the entire backup operation. ^Thus, the backup may be
5341** performed on a live source database without preventing other users from
5342** reading or writing to the source database for an extended period of time.
danielk197704103022009-02-03 16:51:24 +00005343**
drhd68eee02009-12-11 03:44:18 +00005344** ^(To perform a backup operation:
danielk197704103022009-02-03 16:51:24 +00005345** <ol>
drh62b5d2d2009-02-03 18:47:22 +00005346** <li><b>sqlite3_backup_init()</b> is called once to initialize the
5347** backup,
5348** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
danielk197704103022009-02-03 16:51:24 +00005349** the data between the two databases, and finally
drh62b5d2d2009-02-03 18:47:22 +00005350** <li><b>sqlite3_backup_finish()</b> is called to release all resources
danielk197704103022009-02-03 16:51:24 +00005351** associated with the backup operation.
drhd68eee02009-12-11 03:44:18 +00005352** </ol>)^
danielk197704103022009-02-03 16:51:24 +00005353** There should be exactly one call to sqlite3_backup_finish() for each
5354** successful call to sqlite3_backup_init().
5355**
5356** <b>sqlite3_backup_init()</b>
5357**
drhd68eee02009-12-11 03:44:18 +00005358** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
5359** [database connection] associated with the destination database
5360** and the database name, respectively.
5361** ^The database name is "main" for the main database, "temp" for the
5362** temporary database, or the name specified after the AS keyword in
5363** an [ATTACH] statement for an attached database.
5364** ^The S and M arguments passed to
5365** sqlite3_backup_init(D,N,S,M) identify the [database connection]
5366** and database name of the source database, respectively.
5367** ^The source and destination [database connections] (parameters S and D)
5368** must be different or else sqlite3_backup_init(D,N,S,M) will file with
5369** an error.
danielk197704103022009-02-03 16:51:24 +00005370**
drhd68eee02009-12-11 03:44:18 +00005371** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
5372** returned and an error code and error message are store3d in the
5373** destination [database connection] D.
5374** ^The error code and message for the failed call to sqlite3_backup_init()
5375** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
5376** [sqlite3_errmsg16()] functions.
5377** ^A successful call to sqlite3_backup_init() returns a pointer to an
5378** [sqlite3_backup] object.
5379** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
danielk197704103022009-02-03 16:51:24 +00005380** sqlite3_backup_finish() functions to perform the specified backup
5381** operation.
5382**
5383** <b>sqlite3_backup_step()</b>
5384**
drhd68eee02009-12-11 03:44:18 +00005385** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
5386** the source and destination databases specified by [sqlite3_backup] object B.
5387** ^If N is negative value, all remaining source pages are copied.
5388** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
5389** are still more pages to be copied, then the function resturns [SQLITE_OK].
5390** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
5391** from source to destination, then it returns [SQLITE_DONE].
5392** ^If an error occurs while running sqlite3_backup_step(B,N),
5393** then an [error code] is returned. ^As well as [SQLITE_OK] and
drh62b5d2d2009-02-03 18:47:22 +00005394** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
5395** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
5396** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
danielk197704103022009-02-03 16:51:24 +00005397**
drhd68eee02009-12-11 03:44:18 +00005398** ^The sqlite3_backup_step() might return [SQLITE_READONLY] if the destination
5399** database was opened read-only or if
danielk197704103022009-02-03 16:51:24 +00005400** the destination is an in-memory database with a different page size
5401** from the source database.
5402**
drhd68eee02009-12-11 03:44:18 +00005403** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
drh62b5d2d2009-02-03 18:47:22 +00005404** the [sqlite3_busy_handler | busy-handler function]
drhd68eee02009-12-11 03:44:18 +00005405** is invoked (if one is specified). ^If the
danielk197704103022009-02-03 16:51:24 +00005406** busy-handler returns non-zero before the lock is available, then
drhd68eee02009-12-11 03:44:18 +00005407** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
5408** sqlite3_backup_step() can be retried later. ^If the source
drh62b5d2d2009-02-03 18:47:22 +00005409** [database connection]
danielk197704103022009-02-03 16:51:24 +00005410** is being used to write to the source database when sqlite3_backup_step()
drhd68eee02009-12-11 03:44:18 +00005411** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
5412** case the call to sqlite3_backup_step() can be retried later on. ^(If
drh62b5d2d2009-02-03 18:47:22 +00005413** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
5414** [SQLITE_READONLY] is returned, then
danielk197704103022009-02-03 16:51:24 +00005415** there is no point in retrying the call to sqlite3_backup_step(). These
drhd68eee02009-12-11 03:44:18 +00005416** errors are considered fatal.)^ The application must accept
danielk197704103022009-02-03 16:51:24 +00005417** that the backup operation has failed and pass the backup operation handle
5418** to the sqlite3_backup_finish() to release associated resources.
5419**
drhd68eee02009-12-11 03:44:18 +00005420** ^The first call to sqlite3_backup_step() obtains an exclusive lock
5421** on the destination file. ^The exclusive lock is not released until either
danielk197704103022009-02-03 16:51:24 +00005422** sqlite3_backup_finish() is called or the backup operation is complete
drhd68eee02009-12-11 03:44:18 +00005423** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
5424** sqlite3_backup_step() obtains a [shared lock] on the source database that
5425** lasts for the duration of the sqlite3_backup_step() call.
5426** ^Because the source database is not locked between calls to
5427** sqlite3_backup_step(), the source database may be modified mid-way
5428** through the backup process. ^If the source database is modified by an
danielk197704103022009-02-03 16:51:24 +00005429** external process or via a database connection other than the one being
drhd68eee02009-12-11 03:44:18 +00005430** used by the backup operation, then the backup will be automatically
5431** restarted by the next call to sqlite3_backup_step(). ^If the source
danielk197704103022009-02-03 16:51:24 +00005432** database is modified by the using the same database connection as is used
drhd68eee02009-12-11 03:44:18 +00005433** by the backup operation, then the backup database is automatically
danielk197704103022009-02-03 16:51:24 +00005434** updated at the same time.
5435**
5436** <b>sqlite3_backup_finish()</b>
5437**
drhd68eee02009-12-11 03:44:18 +00005438** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
5439** application wishes to abandon the backup operation, the application
5440** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
5441** ^The sqlite3_backup_finish() interfaces releases all
5442** resources associated with the [sqlite3_backup] object.
5443** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
5444** active write-transaction on the destination database is rolled back.
5445** The [sqlite3_backup] object is invalid
danielk197704103022009-02-03 16:51:24 +00005446** and may not be used following a call to sqlite3_backup_finish().
5447**
drhd68eee02009-12-11 03:44:18 +00005448** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
5449** sqlite3_backup_step() errors occurred, regardless or whether or not
5450** sqlite3_backup_step() completed.
5451** ^If an out-of-memory condition or IO error occurred during any prior
5452** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
5453** sqlite3_backup_finish() returns the corresponding [error code].
danielk197704103022009-02-03 16:51:24 +00005454**
drhd68eee02009-12-11 03:44:18 +00005455** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
5456** is not a permanent error and does not affect the return value of
danielk197704103022009-02-03 16:51:24 +00005457** sqlite3_backup_finish().
5458**
5459** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b>
5460**
drhd68eee02009-12-11 03:44:18 +00005461** ^Each call to sqlite3_backup_step() sets two values inside
5462** the [sqlite3_backup] object: the number of pages still to be backed
5463** up and the total number of pages in the source databae file.
5464** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
5465** retrieve these two values, respectively.
danielk197704103022009-02-03 16:51:24 +00005466**
drhd68eee02009-12-11 03:44:18 +00005467** ^The values returned by these functions are only updated by
5468** sqlite3_backup_step(). ^If the source database is modified during a backup
danielk197704103022009-02-03 16:51:24 +00005469** operation, then the values are not updated to account for any extra
5470** pages that need to be updated or the size of the source database file
5471** changing.
5472**
5473** <b>Concurrent Usage of Database Handles</b>
5474**
drhd68eee02009-12-11 03:44:18 +00005475** ^The source [database connection] may be used by the application for other
danielk197704103022009-02-03 16:51:24 +00005476** purposes while a backup operation is underway or being initialized.
drhd68eee02009-12-11 03:44:18 +00005477** ^If SQLite is compiled and configured to support threadsafe database
danielk197704103022009-02-03 16:51:24 +00005478** connections, then the source database connection may be used concurrently
5479** from within other threads.
5480**
drhd68eee02009-12-11 03:44:18 +00005481** However, the application must guarantee that the destination
5482** [database connection] is not passed to any other API (by any thread) after
danielk197704103022009-02-03 16:51:24 +00005483** sqlite3_backup_init() is called and before the corresponding call to
drhd68eee02009-12-11 03:44:18 +00005484** sqlite3_backup_finish(). SQLite does not currently check to see
5485** if the application incorrectly accesses the destination [database connection]
5486** and so no error code is reported, but the operations may malfunction
5487** nevertheless. Use of the destination database connection while a
5488** backup is in progress might also also cause a mutex deadlock.
danielk197704103022009-02-03 16:51:24 +00005489**
drhd68eee02009-12-11 03:44:18 +00005490** If running in [shared cache mode], the application must
danielk197704103022009-02-03 16:51:24 +00005491** guarantee that the shared cache used by the destination database
5492** is not accessed while the backup is running. In practice this means
drhd68eee02009-12-11 03:44:18 +00005493** that the application must guarantee that the disk file being
danielk197704103022009-02-03 16:51:24 +00005494** backed up to is not accessed by any connection within the process,
5495** not just the specific connection that was passed to sqlite3_backup_init().
5496**
drh27b3b842009-02-03 18:25:13 +00005497** The [sqlite3_backup] object itself is partially threadsafe. Multiple
danielk197704103022009-02-03 16:51:24 +00005498** threads may safely make multiple concurrent calls to sqlite3_backup_step().
5499** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
5500** APIs are not strictly speaking threadsafe. If they are invoked at the
5501** same time as another thread is invoking sqlite3_backup_step() it is
5502** possible that they return invalid values.
5503*/
danielk197704103022009-02-03 16:51:24 +00005504sqlite3_backup *sqlite3_backup_init(
5505 sqlite3 *pDest, /* Destination database handle */
5506 const char *zDestName, /* Destination database name */
5507 sqlite3 *pSource, /* Source database handle */
5508 const char *zSourceName /* Source database name */
5509);
5510int sqlite3_backup_step(sqlite3_backup *p, int nPage);
5511int sqlite3_backup_finish(sqlite3_backup *p);
5512int sqlite3_backup_remaining(sqlite3_backup *p);
5513int sqlite3_backup_pagecount(sqlite3_backup *p);
5514
5515/*
danielk1977404ca072009-03-16 13:19:36 +00005516** CAPI3REF: Unlock Notification
5517** EXPERIMENTAL
5518**
drhd68eee02009-12-11 03:44:18 +00005519** ^When running in shared-cache mode, a database operation may fail with
drh89487472009-03-16 13:37:02 +00005520** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
danielk1977404ca072009-03-16 13:19:36 +00005521** individual tables within the shared-cache cannot be obtained. See
5522** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
drhd68eee02009-12-11 03:44:18 +00005523** ^This API may be used to register a callback that SQLite will invoke
danielk1977404ca072009-03-16 13:19:36 +00005524** when the connection currently holding the required lock relinquishes it.
drhd68eee02009-12-11 03:44:18 +00005525** ^This API is only available if the library was compiled with the
drh89487472009-03-16 13:37:02 +00005526** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
danielk1977404ca072009-03-16 13:19:36 +00005527**
5528** See Also: [Using the SQLite Unlock Notification Feature].
5529**
drhd68eee02009-12-11 03:44:18 +00005530** ^Shared-cache locks are released when a database connection concludes
danielk1977404ca072009-03-16 13:19:36 +00005531** its current transaction, either by committing it or rolling it back.
5532**
drhd68eee02009-12-11 03:44:18 +00005533** ^When a connection (known as the blocked connection) fails to obtain a
danielk1977404ca072009-03-16 13:19:36 +00005534** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
5535** identity of the database connection (the blocking connection) that
drhd68eee02009-12-11 03:44:18 +00005536** has locked the required resource is stored internally. ^After an
danielk1977404ca072009-03-16 13:19:36 +00005537** application receives an SQLITE_LOCKED error, it may call the
5538** sqlite3_unlock_notify() method with the blocked connection handle as
5539** the first argument to register for a callback that will be invoked
drhd68eee02009-12-11 03:44:18 +00005540** when the blocking connections current transaction is concluded. ^The
danielk1977404ca072009-03-16 13:19:36 +00005541** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
5542** call that concludes the blocking connections transaction.
5543**
drhd68eee02009-12-11 03:44:18 +00005544** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
danielk1977404ca072009-03-16 13:19:36 +00005545** there is a chance that the blocking connection will have already
5546** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
5547** If this happens, then the specified callback is invoked immediately,
drhd68eee02009-12-11 03:44:18 +00005548** from within the call to sqlite3_unlock_notify().)^
danielk1977404ca072009-03-16 13:19:36 +00005549**
drhd68eee02009-12-11 03:44:18 +00005550** ^If the blocked connection is attempting to obtain a write-lock on a
danielk1977404ca072009-03-16 13:19:36 +00005551** shared-cache table, and more than one other connection currently holds
5552** a read-lock on the same table, then SQLite arbitrarily selects one of
5553** the other connections to use as the blocking connection.
5554**
drhd68eee02009-12-11 03:44:18 +00005555** ^(There may be at most one unlock-notify callback registered by a
danielk1977404ca072009-03-16 13:19:36 +00005556** blocked connection. If sqlite3_unlock_notify() is called when the
5557** blocked connection already has a registered unlock-notify callback,
drhd68eee02009-12-11 03:44:18 +00005558** then the new callback replaces the old.) ^If sqlite3_unlock_notify() is
danielk1977404ca072009-03-16 13:19:36 +00005559** called with a NULL pointer as its second argument, then any existing
drhd68eee02009-12-11 03:44:18 +00005560** unlock-notify callback is cancelled. ^The blocked connections
danielk1977404ca072009-03-16 13:19:36 +00005561** unlock-notify callback may also be canceled by closing the blocked
5562** connection using [sqlite3_close()].
5563**
5564** The unlock-notify callback is not reentrant. If an application invokes
5565** any sqlite3_xxx API functions from within an unlock-notify callback, a
5566** crash or deadlock may be the result.
5567**
drhd68eee02009-12-11 03:44:18 +00005568** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
danielk1977404ca072009-03-16 13:19:36 +00005569** returns SQLITE_OK.
5570**
5571** <b>Callback Invocation Details</b>
5572**
5573** When an unlock-notify callback is registered, the application provides a
5574** single void* pointer that is passed to the callback when it is invoked.
5575** However, the signature of the callback function allows SQLite to pass
5576** it an array of void* context pointers. The first argument passed to
5577** an unlock-notify callback is a pointer to an array of void* pointers,
5578** and the second is the number of entries in the array.
5579**
5580** When a blocking connections transaction is concluded, there may be
5581** more than one blocked connection that has registered for an unlock-notify
drhd68eee02009-12-11 03:44:18 +00005582** callback. ^If two or more such blocked connections have specified the
danielk1977404ca072009-03-16 13:19:36 +00005583** same callback function, then instead of invoking the callback function
5584** multiple times, it is invoked once with the set of void* context pointers
5585** specified by the blocked connections bundled together into an array.
5586** This gives the application an opportunity to prioritize any actions
5587** related to the set of unblocked database connections.
5588**
5589** <b>Deadlock Detection</b>
5590**
5591** Assuming that after registering for an unlock-notify callback a
5592** database waits for the callback to be issued before taking any further
5593** action (a reasonable assumption), then using this API may cause the
5594** application to deadlock. For example, if connection X is waiting for
5595** connection Y's transaction to be concluded, and similarly connection
5596** Y is waiting on connection X's transaction, then neither connection
5597** will proceed and the system may remain deadlocked indefinitely.
5598**
5599** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
drhd68eee02009-12-11 03:44:18 +00005600** detection. ^If a given call to sqlite3_unlock_notify() would put the
danielk1977404ca072009-03-16 13:19:36 +00005601** system in a deadlocked state, then SQLITE_LOCKED is returned and no
5602** unlock-notify callback is registered. The system is said to be in
5603** a deadlocked state if connection A has registered for an unlock-notify
5604** callback on the conclusion of connection B's transaction, and connection
5605** B has itself registered for an unlock-notify callback when connection
drhd68eee02009-12-11 03:44:18 +00005606** A's transaction is concluded. ^Indirect deadlock is also detected, so
danielk1977404ca072009-03-16 13:19:36 +00005607** the system is also considered to be deadlocked if connection B has
5608** registered for an unlock-notify callback on the conclusion of connection
drhd68eee02009-12-11 03:44:18 +00005609** C's transaction, where connection C is waiting on connection A. ^Any
danielk1977404ca072009-03-16 13:19:36 +00005610** number of levels of indirection are allowed.
5611**
5612** <b>The "DROP TABLE" Exception</b>
5613**
5614** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
5615** always appropriate to call sqlite3_unlock_notify(). There is however,
5616** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
5617** SQLite checks if there are any currently executing SELECT statements
5618** that belong to the same connection. If there are, SQLITE_LOCKED is
5619** returned. In this case there is no "blocking connection", so invoking
5620** sqlite3_unlock_notify() results in the unlock-notify callback being
5621** invoked immediately. If the application then re-attempts the "DROP TABLE"
5622** or "DROP INDEX" query, an infinite loop might be the result.
5623**
5624** One way around this problem is to check the extended error code returned
drhd68eee02009-12-11 03:44:18 +00005625** by an sqlite3_step() call. ^(If there is a blocking connection, then the
danielk1977404ca072009-03-16 13:19:36 +00005626** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
5627** the special "DROP TABLE/INDEX" case, the extended error code is just
drhd68eee02009-12-11 03:44:18 +00005628** SQLITE_LOCKED.)^
danielk1977404ca072009-03-16 13:19:36 +00005629*/
5630int sqlite3_unlock_notify(
5631 sqlite3 *pBlocked, /* Waiting connection */
5632 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
5633 void *pNotifyArg /* Argument to pass to xNotify */
5634);
5635
danielk1977ee0484c2009-07-28 16:44:26 +00005636
5637/*
5638** CAPI3REF: String Comparison
5639** EXPERIMENTAL
5640**
drhd68eee02009-12-11 03:44:18 +00005641** ^The [sqlite3_strnicmp()] API allows applications and extensions to
danielk1977ee0484c2009-07-28 16:44:26 +00005642** compare the contents of two buffers containing UTF-8 strings in a
5643** case-indendent fashion, using the same definition of case independence
5644** that SQLite uses internally when comparing identifiers.
5645*/
5646int sqlite3_strnicmp(const char *, const char *, int);
5647
danielk1977404ca072009-03-16 13:19:36 +00005648/*
drhb37df7b2005-10-13 02:09:49 +00005649** Undo the hack that converts floating point types to integer for
5650** builds on processors without floating point support.
5651*/
5652#ifdef SQLITE_OMIT_FLOATING_POINT
5653# undef double
5654#endif
5655
drh382c0242001-10-06 16:33:02 +00005656#ifdef __cplusplus
5657} /* End of the 'extern "C"' block */
5658#endif
danielk19774adee202004-05-08 08:23:19 +00005659#endif